# 9.7. icmpspt — Internal-contracted MPS perturbation method¶

The icmpspt module is an interface to a multi-reference perturbation method that uses DMRG (MPS) wavefunctions as the zeroth order wavefunction. The DMRG wavefunction needs to be generated using the dmrgscf solver. The ic-MPSPT solver can be obtained from Sandeep Sharma (sanshar@gmail.com).