14 Core correlation

By default, Molpro only correlates the valence electrons. Inner-shell correlation can be activated using the CORE directive. On this directive the number of core orbitals (not correlated) in each symmetry is given. Just CORE without any numbers means that all electrons are correlated. For example


Normally, it is sufficient to correlate in the electrons in the $n-1$ shell. Note that it makes no sense at all to activate core correlation without using appropriate basis sets. Whenever available, we recommend to use the cc-pwCV$x$Z or aug-cc-pwCV$x$Z basis sets.

molpro@molpro.net 2019-03-21