elements

Symbols and masses for the chemical elements.

This module provides mappings from atomic number to atomic mass and symbol. These dicts were seeded from running the below script using OpenMM 7.7.

It’s not completely clear where OpenMM sourced these values from [1] but they are generally consistent with recent IUPAC values [2].

  1. https://github.com/openmm/openmm/issues/3434#issuecomment-1023406296

  2. https://www.ciaaw.org/publications.htm

import openmm.app

masses = {
    atomic_number: openmm.app.element.Element.getByAtomicNumber(
        atomic_number
    ).mass._value
    for atomic_number in range(1, 117)
}

symbols = {
    atomic_number: openmm.app.element.Element.getByAtomicNumber(atomic_number).symbol
    for atomic_number in range(1, 117)
}

Module Attributes

MASSES

Mapping from atomic number to element symbol

SYMBOLS

Mapping from element symbol to atomic number