Is it a way to request PSI4 to calculate the density-matrix overlap?

Please see equation (9) in https://doi.org/10.1063/1.4986081

Thank you!

Is it a way to request PSI4 to calculate the density-matrix overlap?

Please see equation (9) in https://doi.org/10.1063/1.4986081

Thank you!

Not directly. The SNS-MP2 plugin code can be found here:

All quantities should be found inside.

It looks like the equation reduces to `Tr(Ga*S*Gb*S)`

where `S`

is the overlap matrix and `Ga`

and `Gb`

are the AO density matrices, so the metric should be really simple to calculate.