torchani.units#

Unit conversion factors used in TorchANI

The ANI models work internally in Hartrees (energy), Angstroms (distance), and AMU (mass).

In some example code and scripts we convert to other more commonly used units. Conversion factors are consistent with CODATA 2014 recommendations, which is also consistent with the units used in ASE by default. (However, take into account that ASE uses electronvolt as its base energy unit, so the appropriate conversion factors should always be applied when converting from ASE to TorchANI) Joule-to-kcal conversion is taken from the IUPAC Goldbook. All the conversion factors we use are defined in this module, and convenience functions to convert between different units are provided.

Functions

`angstrom2bohr`	Angstrom to Bohr conversion factor from 2014 CODATA
`bohr2angstrom`	Bohr to Angstrom conversion factor from 2014 CODATA
`ea2debye`	Dipole conversion, eA to Debye from NIST CCCBDB
`ev2kcalmol`	Electronvolt to kcal/mol conversion factor from CODATA 2014
`ev2kcalpermol`	Electronvolt to kcal/mol conversion factor from CODATA 2014
`ev2kjoulemol`	Electronvolt to kJ/mol conversion factor from CODATA 2014
`ev2kjoulepermol`	Electronvolt to kJ/mol conversion factor from CODATA 2014
`hartree2ev`	Hartree to eV conversion factor from 2014 CODATA
`hartree2kcalmol`	Hartree to kJ/mol conversion factor from CODATA 2014
`hartree2kcalpermol`	Hartree to kJ/mol conversion factor from CODATA 2014
`hartree2kjoulemol`	<function hartree2kjoulepermol at 0x74876a012de0>
`hartree2kjoulepermol`	<function hartree2kjoulepermol at 0x74876a012de0>
`mhessian2fconst`	Converts mass-scaled hessian units into mDyne/Angstrom
`sqrt_mhessian2invcm`	Converts sqrt(mass-scaled hessian units) into cm^-1
`sqrt_mhessian2milliev`	Converts sqrt(mass-scaled hessian units) into meV

torchani.units.angstrom2bohr(x)[source]#

Angstrom to Bohr conversion factor from 2014 CODATA

1 Angstrom = 1.8897261258369282 Bohr

torchani.units.bohr2angstrom(x)[source]#

Bohr to Angstrom conversion factor from 2014 CODATA

1 Bohr = 0.5291772105638411 Angstrom

torchani.units.sqrt_mhessian2invcm(x)[source]#

Converts sqrt(mass-scaled hessian units) into cm^-1

Converts form units of sqrt(Hartree / (amu * Angstrom^2)) which are sqrt(units of the mass-scaled hessian matrix) into units of inverse centimeters.

Take into account that to convert the actual eigenvalues of the hessian into wavenumbers it is necessary to multiply by an extra factor of 1 / (2 * pi)

1 sqrt(Hartree / (AMU * Angstrom^2)) = 17091.7006789297 cm^-1

torchani.units.sqrt_mhessian2milliev(x)[source]#

Converts sqrt(mass-scaled hessian units) into meV

Converts form units of sqrt(Hartree / (amu * Angstrom^2)) which are sqrt(units of the mass-scaled hessian matrix) into units of milli-electronvolts.

Take into account that to convert the actual eigenvalues of the hessian into wavenumbers it is necessary to multiply by an extra factor of 1 / (2 * pi)

1 sqrt(Hartree / (AMU * Angstrom^2)) = 2119.1007908167267 meV

torchani.units.mhessian2fconst(x)[source]#

Converts mass-scaled hessian units into mDyne/Angstrom

Converts from units of mass-scaled hessian (Hartree / (amu * Angstrom^2) into force constant units (mDyne/Angstom), where 1 N = 1 * 10^8 mDyne

1 Hartree / (AMU * Angstrom^2) = 23.060548012069496 mDyne/Angstrom

torchani.units.hartree2ev(x)[source]#

Hartree to eV conversion factor from 2014 CODATA

1 Hartree = 27.211386024367243 eV

torchani.units.ev2kjoulepermol(x)[source]#

Electronvolt to kJ/mol conversion factor from CODATA 2014

1 eV = 96.48533288249877 kJ/mol

torchani.units.ev2kcalpermol(x)[source]#

Electronvolt to kcal/mol conversion factor from CODATA 2014

1 eV = 23.060548012069496 kcal/mol

torchani.units.hartree2kjoulepermol(x)[source]#

1 Hartree = 2625.4996387552483 kJ/mol

torchani.units.hartree2kcalpermol(x)[source]#

Hartree to kJ/mol conversion factor from CODATA 2014

1 Hartree = 627.5094738898777 kcal/mol

torchani.units.ea2debye(x)[source]#

Dipole conversion, eA to Debye from NIST CCCBDB

1 Debye = 0.2081943 electron Angstroms

torchani.units.ev2kcalmol(x)#