I am done

rl/Lib/site-packages/sympy/physics/units/definitions/__init__.py

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+from .unit_definitions import (
+    percent, percents,
+    permille,
+    rad, radian, radians,
+    deg, degree, degrees,
+    sr, steradian, steradians,
+    mil, angular_mil, angular_mils,
+    m, meter, meters,
+    kg, kilogram, kilograms,
+    s, second, seconds,
+    A, ampere, amperes,
+    K, kelvin, kelvins,
+    mol, mole, moles,
+    cd, candela, candelas,
+    g, gram, grams,
+    mg, milligram, milligrams,
+    ug, microgram, micrograms,
+    t, tonne, metric_ton,
+    newton, newtons, N,
+    joule, joules, J,
+    watt, watts, W,
+    pascal, pascals, Pa, pa,
+    hertz, hz, Hz,
+    coulomb, coulombs, C,
+    volt, volts, v, V,
+    ohm, ohms,
+    siemens, S, mho, mhos,
+    farad, farads, F,
+    henry, henrys, H,
+    tesla, teslas, T,
+    weber, webers, Wb, wb,
+    optical_power, dioptre, D,
+    lux, lx,
+    katal, kat,
+    gray, Gy,
+    becquerel, Bq,
+    km, kilometer, kilometers,
+    dm, decimeter, decimeters,
+    cm, centimeter, centimeters,
+    mm, millimeter, millimeters,
+    um, micrometer, micrometers, micron, microns,
+    nm, nanometer, nanometers,
+    pm, picometer, picometers,
+    ft, foot, feet,
+    inch, inches,
+    yd, yard, yards,
+    mi, mile, miles,
+    nmi, nautical_mile, nautical_miles,
+    ha, hectare,
+    l, L, liter, liters,
+    dl, dL, deciliter, deciliters,
+    cl, cL, centiliter, centiliters,
+    ml, mL, milliliter, milliliters,
+    ms, millisecond, milliseconds,
+    us, microsecond, microseconds,
+    ns, nanosecond, nanoseconds,
+    ps, picosecond, picoseconds,
+    minute, minutes,
+    h, hour, hours,
+    day, days,
+    anomalistic_year, anomalistic_years,
+    sidereal_year, sidereal_years,
+    tropical_year, tropical_years,
+    common_year, common_years,
+    julian_year, julian_years,
+    draconic_year, draconic_years,
+    gaussian_year, gaussian_years,
+    full_moon_cycle, full_moon_cycles,
+    year, years,
+    G, gravitational_constant,
+    c, speed_of_light,
+    elementary_charge,
+    hbar,
+    planck,
+    eV, electronvolt, electronvolts,
+    avogadro_number,
+    avogadro, avogadro_constant,
+    boltzmann, boltzmann_constant,
+    stefan, stefan_boltzmann_constant,
+    R, molar_gas_constant,
+    faraday_constant,
+    josephson_constant,
+    von_klitzing_constant,
+    Da, dalton, amu, amus, atomic_mass_unit, atomic_mass_constant,
+    me, electron_rest_mass,
+    gee, gees, acceleration_due_to_gravity,
+    u0, magnetic_constant, vacuum_permeability,
+    e0, electric_constant, vacuum_permittivity,
+    Z0, vacuum_impedance,
+    coulomb_constant, coulombs_constant, electric_force_constant,
+    atmosphere, atmospheres, atm,
+    kPa, kilopascal,
+    bar, bars,
+    pound, pounds,
+    psi,
+    dHg0,
+    mmHg, torr,
+    mmu, mmus, milli_mass_unit,
+    quart, quarts,
+    angstrom, angstroms,
+    ly, lightyear, lightyears,
+    au, astronomical_unit, astronomical_units,
+    planck_mass,
+    planck_time,
+    planck_temperature,
+    planck_length,
+    planck_charge,
+    planck_area,
+    planck_volume,
+    planck_momentum,
+    planck_energy,
+    planck_force,
+    planck_power,
+    planck_density,
+    planck_energy_density,
+    planck_intensity,
+    planck_angular_frequency,
+    planck_pressure,
+    planck_current,
+    planck_voltage,
+    planck_impedance,
+    planck_acceleration,
+    bit, bits,
+    byte,
+    kibibyte, kibibytes,
+    mebibyte, mebibytes,
+    gibibyte, gibibytes,
+    tebibyte, tebibytes,
+    pebibyte, pebibytes,
+    exbibyte, exbibytes,
+    curie, rutherford
+)
+
+__all__ = [
+    'percent', 'percents',
+    'permille',
+    'rad', 'radian', 'radians',
+    'deg', 'degree', 'degrees',
+    'sr', 'steradian', 'steradians',
+    'mil', 'angular_mil', 'angular_mils',
+    'm', 'meter', 'meters',
+    'kg', 'kilogram', 'kilograms',
+    's', 'second', 'seconds',
+    'A', 'ampere', 'amperes',
+    'K', 'kelvin', 'kelvins',
+    'mol', 'mole', 'moles',
+    'cd', 'candela', 'candelas',
+    'g', 'gram', 'grams',
+    'mg', 'milligram', 'milligrams',
+    'ug', 'microgram', 'micrograms',
+    't', 'tonne', 'metric_ton',
+    'newton', 'newtons', 'N',
+    'joule', 'joules', 'J',
+    'watt', 'watts', 'W',
+    'pascal', 'pascals', 'Pa', 'pa',
+    'hertz', 'hz', 'Hz',
+    'coulomb', 'coulombs', 'C',
+    'volt', 'volts', 'v', 'V',
+    'ohm', 'ohms',
+    'siemens', 'S', 'mho', 'mhos',
+    'farad', 'farads', 'F',
+    'henry', 'henrys', 'H',
+    'tesla', 'teslas', 'T',
+    'weber', 'webers', 'Wb', 'wb',
+    'optical_power', 'dioptre', 'D',
+    'lux', 'lx',
+    'katal', 'kat',
+    'gray', 'Gy',
+    'becquerel', 'Bq',
+    'km', 'kilometer', 'kilometers',
+    'dm', 'decimeter', 'decimeters',
+    'cm', 'centimeter', 'centimeters',
+    'mm', 'millimeter', 'millimeters',
+    'um', 'micrometer', 'micrometers', 'micron', 'microns',
+    'nm', 'nanometer', 'nanometers',
+    'pm', 'picometer', 'picometers',
+    'ft', 'foot', 'feet',
+    'inch', 'inches',
+    'yd', 'yard', 'yards',
+    'mi', 'mile', 'miles',
+    'nmi', 'nautical_mile', 'nautical_miles',
+    'ha', 'hectare',
+    'l', 'L', 'liter', 'liters',
+    'dl', 'dL', 'deciliter', 'deciliters',
+    'cl', 'cL', 'centiliter', 'centiliters',
+    'ml', 'mL', 'milliliter', 'milliliters',
+    'ms', 'millisecond', 'milliseconds',
+    'us', 'microsecond', 'microseconds',
+    'ns', 'nanosecond', 'nanoseconds',
+    'ps', 'picosecond', 'picoseconds',
+    'minute', 'minutes',
+    'h', 'hour', 'hours',
+    'day', 'days',
+    'anomalistic_year', 'anomalistic_years',
+    'sidereal_year', 'sidereal_years',
+    'tropical_year', 'tropical_years',
+    'common_year', 'common_years',
+    'julian_year', 'julian_years',
+    'draconic_year', 'draconic_years',
+    'gaussian_year', 'gaussian_years',
+    'full_moon_cycle', 'full_moon_cycles',
+    'year', 'years',
+    'G', 'gravitational_constant',
+    'c', 'speed_of_light',
+    'elementary_charge',
+    'hbar',
+    'planck',
+    'eV', 'electronvolt', 'electronvolts',
+    'avogadro_number',
+    'avogadro', 'avogadro_constant',
+    'boltzmann', 'boltzmann_constant',
+    'stefan', 'stefan_boltzmann_constant',
+    'R', 'molar_gas_constant',
+    'faraday_constant',
+    'josephson_constant',
+    'von_klitzing_constant',
+    'Da', 'dalton', 'amu', 'amus', 'atomic_mass_unit', 'atomic_mass_constant',
+    'me', 'electron_rest_mass',
+    'gee', 'gees', 'acceleration_due_to_gravity',
+    'u0', 'magnetic_constant', 'vacuum_permeability',
+    'e0', 'electric_constant', 'vacuum_permittivity',
+    'Z0', 'vacuum_impedance',
+    'coulomb_constant', 'coulombs_constant', 'electric_force_constant',
+    'atmosphere', 'atmospheres', 'atm',
+    'kPa', 'kilopascal',
+    'bar', 'bars',
+    'pound', 'pounds',
+    'psi',
+    'dHg0',
+    'mmHg', 'torr',
+    'mmu', 'mmus', 'milli_mass_unit',
+    'quart', 'quarts',
+    'angstrom', 'angstroms',
+    'ly', 'lightyear', 'lightyears',
+    'au', 'astronomical_unit', 'astronomical_units',
+    'planck_mass',
+    'planck_time',
+    'planck_temperature',
+    'planck_length',
+    'planck_charge',
+    'planck_area',
+    'planck_volume',
+    'planck_momentum',
+    'planck_energy',
+    'planck_force',
+    'planck_power',
+    'planck_density',
+    'planck_energy_density',
+    'planck_intensity',
+    'planck_angular_frequency',
+    'planck_pressure',
+    'planck_current',
+    'planck_voltage',
+    'planck_impedance',
+    'planck_acceleration',
+    'bit', 'bits',
+    'byte',
+    'kibibyte', 'kibibytes',
+    'mebibyte', 'mebibytes',
+    'gibibyte', 'gibibytes',
+    'tebibyte', 'tebibytes',
+    'pebibyte', 'pebibytes',
+    'exbibyte', 'exbibytes',
+    'curie', 'rutherford',
+]

rl/Lib/site-packages/sympy/physics/units/definitions/dimension_definitions.py

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+from sympy.physics.units import Dimension
+
+
+angle = Dimension(name="angle")  # type: Dimension
+
+# base dimensions (MKS)
+length = Dimension(name="length", symbol="L")
+mass = Dimension(name="mass", symbol="M")
+time = Dimension(name="time", symbol="T")
+
+# base dimensions (MKSA not in MKS)
+current = Dimension(name='current', symbol='I')  # type: Dimension
+
+# other base dimensions:
+temperature = Dimension("temperature", "T")  # type: Dimension
+amount_of_substance = Dimension("amount_of_substance")  # type: Dimension
+luminous_intensity = Dimension("luminous_intensity")  # type: Dimension
+
+# derived dimensions (MKS)
+velocity = Dimension(name="velocity")
+acceleration = Dimension(name="acceleration")
+momentum = Dimension(name="momentum")
+force = Dimension(name="force", symbol="F")
+energy = Dimension(name="energy", symbol="E")
+power = Dimension(name="power")
+pressure = Dimension(name="pressure")
+frequency = Dimension(name="frequency", symbol="f")
+action = Dimension(name="action", symbol="A")
+area = Dimension("area")
+volume = Dimension("volume")
+
+# derived dimensions (MKSA not in MKS)
+voltage = Dimension(name='voltage', symbol='U')  # type: Dimension
+impedance = Dimension(name='impedance', symbol='Z')  # type: Dimension
+conductance = Dimension(name='conductance', symbol='G')  # type: Dimension
+capacitance = Dimension(name='capacitance')  # type: Dimension
+inductance = Dimension(name='inductance')  # type: Dimension
+charge = Dimension(name='charge', symbol='Q')  # type: Dimension
+magnetic_density = Dimension(name='magnetic_density', symbol='B')  # type: Dimension
+magnetic_flux = Dimension(name='magnetic_flux')  # type: Dimension
+
+# Dimensions in information theory:
+information = Dimension(name='information')  # type: Dimension

rl/Lib/site-packages/sympy/physics/units/definitions/unit_definitions.py

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+from sympy.physics.units.definitions.dimension_definitions import current, temperature, amount_of_substance, \
+    luminous_intensity, angle, charge, voltage, impedance, conductance, capacitance, inductance, magnetic_density, \
+    magnetic_flux, information
+
+from sympy.core.numbers import (Rational, pi)
+from sympy.core.singleton import S as S_singleton
+from sympy.physics.units.prefixes import kilo, mega, milli, micro, deci, centi, nano, pico, kibi, mebi, gibi, tebi, pebi, exbi
+from sympy.physics.units.quantities import PhysicalConstant, Quantity
+
+One = S_singleton.One
+
+#### UNITS ####
+
+# Dimensionless:
+percent = percents = Quantity("percent", latex_repr=r"\%")
+percent.set_global_relative_scale_factor(Rational(1, 100), One)
+
+permille = Quantity("permille")
+permille.set_global_relative_scale_factor(Rational(1, 1000), One)
+
+
+# Angular units (dimensionless)
+rad = radian = radians = Quantity("radian", abbrev="rad")
+radian.set_global_dimension(angle)
+deg = degree = degrees = Quantity("degree", abbrev="deg", latex_repr=r"^\circ")
+degree.set_global_relative_scale_factor(pi/180, radian)
+sr = steradian = steradians = Quantity("steradian", abbrev="sr")
+mil = angular_mil = angular_mils = Quantity("angular_mil", abbrev="mil")
+
+# Base units:
+m = meter = meters = Quantity("meter", abbrev="m")
+
+# gram; used to define its prefixed units
+g = gram = grams = Quantity("gram", abbrev="g")
+
+# NOTE: the `kilogram` has scale factor 1000. In SI, kg is a base unit, but
+# nonetheless we are trying to be compatible with the `kilo` prefix. In a
+# similar manner, people using CGS or gaussian units could argue that the
+# `centimeter` rather than `meter` is the fundamental unit for length, but the
+# scale factor of `centimeter` will be kept as 1/100 to be compatible with the
+# `centi` prefix.  The current state of the code assumes SI unit dimensions, in
+# the future this module will be modified in order to be unit system-neutral
+# (that is, support all kinds of unit systems).
+kg = kilogram = kilograms = Quantity("kilogram", abbrev="kg")
+kg.set_global_relative_scale_factor(kilo, gram)
+
+s = second = seconds = Quantity("second", abbrev="s")
+A = ampere = amperes = Quantity("ampere", abbrev='A')
+ampere.set_global_dimension(current)
+K = kelvin = kelvins = Quantity("kelvin", abbrev='K')
+kelvin.set_global_dimension(temperature)
+mol = mole = moles = Quantity("mole", abbrev="mol")
+mole.set_global_dimension(amount_of_substance)
+cd = candela = candelas = Quantity("candela", abbrev="cd")
+candela.set_global_dimension(luminous_intensity)
+
+# derived units
+newton = newtons = N = Quantity("newton", abbrev="N")
+
+kilonewton = kilonewtons = kN = Quantity("kilonewton", abbrev="kN")
+kilonewton.set_global_relative_scale_factor(kilo, newton)
+
+meganewton = meganewtons = MN = Quantity("meganewton", abbrev="MN")
+meganewton.set_global_relative_scale_factor(mega, newton)
+
+joule = joules = J = Quantity("joule", abbrev="J")
+watt = watts = W = Quantity("watt", abbrev="W")
+pascal = pascals = Pa = pa = Quantity("pascal", abbrev="Pa")
+hertz = hz = Hz = Quantity("hertz", abbrev="Hz")
+
+# CGS derived units:
+dyne = Quantity("dyne")
+dyne.set_global_relative_scale_factor(One/10**5, newton)
+erg = Quantity("erg")
+erg.set_global_relative_scale_factor(One/10**7, joule)
+
+# MKSA extension to MKS: derived units
+coulomb = coulombs = C = Quantity("coulomb", abbrev='C')
+coulomb.set_global_dimension(charge)
+volt = volts = v = V = Quantity("volt", abbrev='V')
+volt.set_global_dimension(voltage)
+ohm = ohms = Quantity("ohm", abbrev='ohm', latex_repr=r"\Omega")
+ohm.set_global_dimension(impedance)
+siemens = S = mho = mhos = Quantity("siemens", abbrev='S')
+siemens.set_global_dimension(conductance)
+farad = farads = F = Quantity("farad", abbrev='F')
+farad.set_global_dimension(capacitance)
+henry = henrys = H = Quantity("henry", abbrev='H')
+henry.set_global_dimension(inductance)
+tesla = teslas = T = Quantity("tesla", abbrev='T')
+tesla.set_global_dimension(magnetic_density)
+weber = webers = Wb = wb = Quantity("weber", abbrev='Wb')
+weber.set_global_dimension(magnetic_flux)
+
+# CGS units for electromagnetic quantities:
+statampere = Quantity("statampere")
+statcoulomb = statC = franklin = Quantity("statcoulomb", abbrev="statC")
+statvolt = Quantity("statvolt")
+gauss = Quantity("gauss")
+maxwell = Quantity("maxwell")
+debye = Quantity("debye")
+oersted = Quantity("oersted")
+
+# Other derived units:
+optical_power = dioptre = diopter = D = Quantity("dioptre")
+lux = lx = Quantity("lux", abbrev="lx")
+
+# katal is the SI unit of catalytic activity
+katal = kat = Quantity("katal", abbrev="kat")
+
+# gray is the SI unit of absorbed dose
+gray = Gy = Quantity("gray")
+
+# becquerel is the SI unit of radioactivity
+becquerel = Bq = Quantity("becquerel", abbrev="Bq")
+
+
+# Common mass units
+
+mg = milligram = milligrams = Quantity("milligram", abbrev="mg")
+mg.set_global_relative_scale_factor(milli, gram)
+
+ug = microgram = micrograms = Quantity("microgram", abbrev="ug", latex_repr=r"\mu\text{g}")
+ug.set_global_relative_scale_factor(micro, gram)
+
+# Atomic mass constant
+Da = dalton = amu = amus = atomic_mass_unit = atomic_mass_constant = PhysicalConstant("atomic_mass_constant")
+
+t = metric_ton = tonne = Quantity("tonne", abbrev="t")
+tonne.set_global_relative_scale_factor(mega, gram)
+
+# Electron rest mass
+me = electron_rest_mass = Quantity("electron_rest_mass", abbrev="me")
+
+
+# Common length units
+
+km = kilometer = kilometers = Quantity("kilometer", abbrev="km")
+km.set_global_relative_scale_factor(kilo, meter)
+
+dm = decimeter = decimeters = Quantity("decimeter", abbrev="dm")
+dm.set_global_relative_scale_factor(deci, meter)
+
+cm = centimeter = centimeters = Quantity("centimeter", abbrev="cm")
+cm.set_global_relative_scale_factor(centi, meter)
+
+mm = millimeter = millimeters = Quantity("millimeter", abbrev="mm")
+mm.set_global_relative_scale_factor(milli, meter)
+
+um = micrometer = micrometers = micron = microns = \
+    Quantity("micrometer", abbrev="um", latex_repr=r'\mu\text{m}')
+um.set_global_relative_scale_factor(micro, meter)
+
+nm = nanometer = nanometers = Quantity("nanometer", abbrev="nm")
+nm.set_global_relative_scale_factor(nano, meter)
+
+pm = picometer = picometers = Quantity("picometer", abbrev="pm")
+pm.set_global_relative_scale_factor(pico, meter)
+
+ft = foot = feet = Quantity("foot", abbrev="ft")
+ft.set_global_relative_scale_factor(Rational(3048, 10000), meter)
+
+inch = inches = Quantity("inch")
+inch.set_global_relative_scale_factor(Rational(1, 12), foot)
+
+yd = yard = yards = Quantity("yard", abbrev="yd")
+yd.set_global_relative_scale_factor(3, feet)
+
+mi = mile = miles = Quantity("mile")
+mi.set_global_relative_scale_factor(5280, feet)
+
+nmi = nautical_mile = nautical_miles = Quantity("nautical_mile")
+nmi.set_global_relative_scale_factor(6076, feet)
+
+angstrom = angstroms = Quantity("angstrom", latex_repr=r'\r{A}')
+angstrom.set_global_relative_scale_factor(Rational(1, 10**10), meter)
+
+
+# Common volume and area units
+
+ha = hectare = Quantity("hectare", abbrev="ha")
+
+l = L = liter = liters = Quantity("liter", abbrev="l")
+
+dl = dL = deciliter = deciliters = Quantity("deciliter", abbrev="dl")
+dl.set_global_relative_scale_factor(Rational(1, 10), liter)
+
+cl = cL = centiliter = centiliters = Quantity("centiliter", abbrev="cl")
+cl.set_global_relative_scale_factor(Rational(1, 100), liter)
+
+ml = mL = milliliter = milliliters = Quantity("milliliter", abbrev="ml")
+ml.set_global_relative_scale_factor(Rational(1, 1000), liter)
+
+
+# Common time units
+
+ms = millisecond = milliseconds = Quantity("millisecond", abbrev="ms")
+millisecond.set_global_relative_scale_factor(milli, second)
+
+us = microsecond = microseconds = Quantity("microsecond", abbrev="us", latex_repr=r'\mu\text{s}')
+microsecond.set_global_relative_scale_factor(micro, second)
+
+ns = nanosecond = nanoseconds = Quantity("nanosecond", abbrev="ns")
+nanosecond.set_global_relative_scale_factor(nano, second)
+
+ps = picosecond = picoseconds = Quantity("picosecond", abbrev="ps")
+picosecond.set_global_relative_scale_factor(pico, second)
+
+minute = minutes = Quantity("minute")
+minute.set_global_relative_scale_factor(60, second)
+
+h = hour = hours = Quantity("hour")
+hour.set_global_relative_scale_factor(60, minute)
+
+day = days = Quantity("day")
+day.set_global_relative_scale_factor(24, hour)
+
+anomalistic_year = anomalistic_years = Quantity("anomalistic_year")
+anomalistic_year.set_global_relative_scale_factor(365.259636, day)
+
+sidereal_year = sidereal_years = Quantity("sidereal_year")
+sidereal_year.set_global_relative_scale_factor(31558149.540, seconds)
+
+tropical_year = tropical_years = Quantity("tropical_year")
+tropical_year.set_global_relative_scale_factor(365.24219, day)
+
+common_year = common_years = Quantity("common_year")
+common_year.set_global_relative_scale_factor(365, day)
+
+julian_year = julian_years = Quantity("julian_year")
+julian_year.set_global_relative_scale_factor((365 + One/4), day)
+
+draconic_year = draconic_years = Quantity("draconic_year")
+draconic_year.set_global_relative_scale_factor(346.62, day)
+
+gaussian_year = gaussian_years = Quantity("gaussian_year")
+gaussian_year.set_global_relative_scale_factor(365.2568983, day)
+
+full_moon_cycle = full_moon_cycles = Quantity("full_moon_cycle")
+full_moon_cycle.set_global_relative_scale_factor(411.78443029, day)
+
+year = years = tropical_year
+
+
+#### CONSTANTS ####
+
+# Newton constant
+G = gravitational_constant = PhysicalConstant("gravitational_constant", abbrev="G")
+
+# speed of light
+c = speed_of_light = PhysicalConstant("speed_of_light", abbrev="c")
+
+# elementary charge
+elementary_charge = PhysicalConstant("elementary_charge", abbrev="e")
+
+# Planck constant
+planck = PhysicalConstant("planck", abbrev="h")
+
+# Reduced Planck constant
+hbar = PhysicalConstant("hbar", abbrev="hbar")
+
+# Electronvolt
+eV = electronvolt = electronvolts = PhysicalConstant("electronvolt", abbrev="eV")
+
+# Avogadro number
+avogadro_number = PhysicalConstant("avogadro_number")
+
+# Avogadro constant
+avogadro = avogadro_constant = PhysicalConstant("avogadro_constant")
+
+# Boltzmann constant
+boltzmann = boltzmann_constant = PhysicalConstant("boltzmann_constant")
+
+# Stefan-Boltzmann constant
+stefan = stefan_boltzmann_constant = PhysicalConstant("stefan_boltzmann_constant")
+
+# Molar gas constant
+R = molar_gas_constant = PhysicalConstant("molar_gas_constant", abbrev="R")
+
+# Faraday constant
+faraday_constant = PhysicalConstant("faraday_constant")
+
+# Josephson constant
+josephson_constant = PhysicalConstant("josephson_constant", abbrev="K_j")
+
+# Von Klitzing constant
+von_klitzing_constant = PhysicalConstant("von_klitzing_constant", abbrev="R_k")
+
+# Acceleration due to gravity (on the Earth surface)
+gee = gees = acceleration_due_to_gravity = PhysicalConstant("acceleration_due_to_gravity", abbrev="g")
+
+# magnetic constant:
+u0 = magnetic_constant = vacuum_permeability = PhysicalConstant("magnetic_constant")
+
+# electric constat:
+e0 = electric_constant = vacuum_permittivity = PhysicalConstant("vacuum_permittivity")
+
+# vacuum impedance:
+Z0 = vacuum_impedance = PhysicalConstant("vacuum_impedance", abbrev='Z_0', latex_repr=r'Z_{0}')
+
+# Coulomb's constant:
+coulomb_constant = coulombs_constant = electric_force_constant = \
+    PhysicalConstant("coulomb_constant", abbrev="k_e")
+
+
+atmosphere = atmospheres = atm = Quantity("atmosphere", abbrev="atm")
+
+kPa = kilopascal = Quantity("kilopascal", abbrev="kPa")
+kilopascal.set_global_relative_scale_factor(kilo, Pa)
+
+bar = bars = Quantity("bar", abbrev="bar")
+
+pound = pounds = Quantity("pound")  # exact
+
+psi = Quantity("psi")
+
+dHg0 = 13.5951  # approx value at 0 C
+mmHg = torr = Quantity("mmHg")
+
+atmosphere.set_global_relative_scale_factor(101325, pascal)
+bar.set_global_relative_scale_factor(100, kPa)
+pound.set_global_relative_scale_factor(Rational(45359237, 100000000), kg)
+
+mmu = mmus = milli_mass_unit = Quantity("milli_mass_unit")
+
+quart = quarts = Quantity("quart")
+
+
+# Other convenient units and magnitudes
+
+ly = lightyear = lightyears = Quantity("lightyear", abbrev="ly")
+
+au = astronomical_unit = astronomical_units = Quantity("astronomical_unit", abbrev="AU")
+
+
+# Fundamental Planck units:
+planck_mass = Quantity("planck_mass", abbrev="m_P", latex_repr=r'm_\text{P}')
+
+planck_time = Quantity("planck_time", abbrev="t_P", latex_repr=r't_\text{P}')
+
+planck_temperature = Quantity("planck_temperature", abbrev="T_P",
+                              latex_repr=r'T_\text{P}')
+
+planck_length = Quantity("planck_length", abbrev="l_P", latex_repr=r'l_\text{P}')
+
+planck_charge = Quantity("planck_charge", abbrev="q_P", latex_repr=r'q_\text{P}')
+
+
+# Derived Planck units:
+planck_area = Quantity("planck_area")
+
+planck_volume = Quantity("planck_volume")
+
+planck_momentum = Quantity("planck_momentum")
+
+planck_energy = Quantity("planck_energy", abbrev="E_P", latex_repr=r'E_\text{P}')
+
+planck_force = Quantity("planck_force", abbrev="F_P", latex_repr=r'F_\text{P}')
+
+planck_power = Quantity("planck_power", abbrev="P_P", latex_repr=r'P_\text{P}')
+
+planck_density = Quantity("planck_density", abbrev="rho_P", latex_repr=r'\rho_\text{P}')
+
+planck_energy_density = Quantity("planck_energy_density", abbrev="rho^E_P")
+
+planck_intensity = Quantity("planck_intensity", abbrev="I_P", latex_repr=r'I_\text{P}')
+
+planck_angular_frequency = Quantity("planck_angular_frequency", abbrev="omega_P",
+                                    latex_repr=r'\omega_\text{P}')
+
+planck_pressure = Quantity("planck_pressure", abbrev="p_P", latex_repr=r'p_\text{P}')
+
+planck_current = Quantity("planck_current", abbrev="I_P", latex_repr=r'I_\text{P}')
+
+planck_voltage = Quantity("planck_voltage", abbrev="V_P", latex_repr=r'V_\text{P}')
+
+planck_impedance = Quantity("planck_impedance", abbrev="Z_P", latex_repr=r'Z_\text{P}')
+
+planck_acceleration = Quantity("planck_acceleration", abbrev="a_P",
+                               latex_repr=r'a_\text{P}')
+
+
+# Information theory units:
+bit = bits = Quantity("bit")
+bit.set_global_dimension(information)
+
+byte = bytes = Quantity("byte")
+
+kibibyte = kibibytes = Quantity("kibibyte")
+mebibyte = mebibytes = Quantity("mebibyte")
+gibibyte = gibibytes = Quantity("gibibyte")
+tebibyte = tebibytes = Quantity("tebibyte")
+pebibyte = pebibytes = Quantity("pebibyte")
+exbibyte = exbibytes = Quantity("exbibyte")
+
+byte.set_global_relative_scale_factor(8, bit)
+kibibyte.set_global_relative_scale_factor(kibi, byte)
+mebibyte.set_global_relative_scale_factor(mebi, byte)
+gibibyte.set_global_relative_scale_factor(gibi, byte)
+tebibyte.set_global_relative_scale_factor(tebi, byte)
+pebibyte.set_global_relative_scale_factor(pebi, byte)
+exbibyte.set_global_relative_scale_factor(exbi, byte)
+
+# Older units for radioactivity
+curie = Ci = Quantity("curie", abbrev="Ci")
+
+rutherford = Rd = Quantity("rutherford", abbrev="Rd")