Energy Units and Conversion using FORTRAN

This is the Fortran 77 program for energy conversion. Convert energy from Hartree to eV, kJ/mol, kcal/mol, cm-1, and V.

Why FORTRAN?

FORTRAN, a low-level programming language, is

fast for scientific calculation. However, you would not see the difference in the speed of calculation between Fortran and other programming languages.
easy to list-directed formatting, editing is controlled by the types and lengths of the data being read or written.
able to run on any Linux distribution and any platform with a compiled application (binary file).

conv.f

c-----------------------------------------------

c Energy conversion

c Hartrees --> eV, kJ/mol, kcal/mol, cm-1, and V

c-----------------------------------------------

program convert_energy

real Har, eV, kJmol, kCmol, cm, V, K, Kb

character ARGV*10

c N=iargc()

call getarg(1,ARGV)

c RARGV will convert ARGV into floating-point integer.

read (ARGV,*) rargv

c Assign ARGV to Har

read (ARGV,*) Har

eV = Har * 27.211399

J = Har * 4359.7482e-21

kJmol = Har * 2625.5002

kCmol = Har * 627.5096080305927

cm = Har * 219474.63

V = Har * 27.211598534895728

write (6,'(/,a,/)') " === Energy Converter ==="

write (6,100) Har, "Hartree"

write (6,100) eV, "eV"

write (6,200) J, "J"

write (6,100) kJmol, "kJ/mol"

write (6,100) kCmol, "kCal/mol"

write (6,100) cm, "cm^-1"

write (6,100) V, "V for 1 e- transfer"

write (6,100)

100 format (f20.5,2x,a)

200 format (e20.5,2x,a)

stop

end

Compilation and Usage

1. Compile program

use GNU Fortran compiler

gfortran conv.f -o conv

use Intel Fortran compiler

ifort conv.f -o conv

2. Execute conv program with energy without Hartree unit

For example, 1.0 Hartree

./conv 1.0

Example of Output

=== Energy Converter ===

1.00000 Hartree

27.21140 eV

0.43597E-17 J

2625.50024 kJ/mol

627.50958 kCal/mol

219474.62500 cm^-1

27.21160 V for 1 e- transfer

Rangsiman Ketkaew