From owner-chemistry@ccl.net Tue Dec  7 09:01:00 2021
From: "Kavya Vinod kavya.vnd20#iisertvm.ac.in" <owner-chemistry!=!server.ccl.net>
To: CCL
Subject: CCL: CASSCF on PDI molecule
Message-Id: <-54529-211207002252-3729-+vmeb0v6lNiBIU478WRYNA!=!server.ccl.net>
X-Original-From: "Kavya  Vinod" <kavya.vnd20|a|iisertvm.ac.in>
Date: Tue, 7 Dec 2021 00:22:51 -0500


Sent to CCL by: "Kavya  Vinod" [kavya.vnd20:+:iisertvm.ac.in]
I am trying to perform a CASSCF calculation on a perylenediimide chromophore 
with selenium atom on it using Orca 4.2.1. The initial CASSCF calculation on 
the system with the guess active space (4,4) has difficulty undergoing normal 
termination. I have tried CASSCF(6,6) in benzene which has terminated 
successfully without any convergence difficulties. Do I need to modify the 
active space even further?
Any advice in this regard will be deeply appreciated.