E-CAM Physical Constant module

Purpose of Module

This module enables to use fundamental physical constants (speed of light in vacuum, Planck constant … and isotopic masses). Two versions can be selected:

  • The CODATA 2006 ones, downloaded from NIST and the NIST masses downloaded in 2012 (default).
  • Constants and masses from the 70th edition of the Handbook of Chemistry and Physics.

From these fundamental constants, some conversion factors are calculated automatically and can be used easily.

Remark: the actual mass values of the NIST web page differ slightly from the module ones.

Background Information

This module has been extracted and modified from the ElVibRot-Tnum-Tnum code (ElVibRot_f90-v80.13-Tnum28.9-Tana5.1). This pre-E-CAM version can be downloaded here.


Dependencies: this module needs the fortran modules in the Source_Lib/sub_system directory.

Build the module (with dependencies):

make PhysConst

Build the module documentation (with doxygen):

make doxy


Two example data/script files:


To test the installation, you can run both test examples.

cd Examples/exa_PhysicalConstants ; ./run_tests

The results will be compared to previous results in Examples/exa_PhysicalConstants/output_17dec2016 file.

Source Code

The source code can be downloaded from the E-CAM GitLab service.