# Optimize and Frequency with formatted check point

Hi there, I was quite a familiar with gaussian environment where the frequencies can be calculated and read with external programs as gview, avogadro. Is there any special keywords that invoke frequency?
In many instances, the .fchk file is required to calculate density, esp and to create .cube files etc. how can I create one?

PSI4 is able to output molden: http://psicode.org/psi4manual/master/molden.html
and FCHK: http://psicode.org/psi4manual/master/fchk.html

You can view normal modes like this: http://psicode.org/psi4manual/master/freq.html#molden-interface-keywords