Older version of Molden (Molden3.5 and older) had static memory allocation for orbitals, newer versions use dynamic memory allocation for the orbitals and do not suffer from the problem discussed below.
When using big Ab Initio calculations Molden can give an error message:
Exceeding MaxNum of Orbitals!
Default Molden is configured for a maximum of 256 orbitals and 150 atoms.
In the source directory there is a script ""change_parameter" which you
can apply before compiling again, it will change the maximum number of
orbitals to 1024 and the maximum number of atoms to 300.
It is handy to keep around a copy of the "small" executable however,
since the "big" executable is a memory hog.
So copy the old executable:
cp molden molden.256 change_parameter make