Interfaces and QM/MM
ORCA can be interfaced to various other programs (geometry optimizers, MD programs, QM/MM programs). These programs then communicate with ORCA via the automatic creation of inputfiles, running the ORCA inputfiles and reading e.g. the energy and gradient from the ORCA output. The energy and gradient from ORCA (possibly combined with an MM gradient first) is then e.g. fed to the geometry optimization/MD program to predict the next step.
See chapter 8.14 in the manual for information about the QM/MM capabilities of ORCA and interfaces. ORCA is an excellent QM program for QM/MM calculations, being e.g. a fast DFT and MP2 programs and supporting electrostatic embedding (pointcharges and pointcharge gradients).
Below is an incomplete list of available ORCA interfaces to QM/MM programs or optimizer/MD programs.
ORCA and ASE interface
See ORCA and ASE page.
ORCA & Gromacs interface
See chapter 5.15.1 in the manual. Or this page.
ORCA & NAMD
See NAMD page.
ORCA & PUPIL
See PUPIL page
ORCA & Cuby
See Cuby website
ORCA & PDynamo interface
See pDynamo Wiki and chapter 5.15.2 in the manual.
ORCA & Chemshell interface
ORCA can be used as the QM program in geometry optimizations, MD simulations, NEB calculations etc. in both QM and QM/MM calculations.
See ORCA & Chemshell chapter