From owner-chemistry@ccl.net Sat Jun 30 14:24:00 2018
From: "Ghazwan Fadhil ghazwan_fadhil a yahoo.co.uk" <owner-chemistry^server.ccl.net>
To: CCL
Subject: CCL:G: Cl became unbonded after DFT GO
Message-Id: <-53364-180630025418-8350-f4RJAO7rYTqen/Yuz+/oTw^server.ccl.net>
X-Original-From: "Ghazwan  Fadhil" <ghazwan_fadhil*yahoo.co.uk>
Date: Sat, 30 Jun 2018 02:54:15 -0400


Sent to CCL by: "Ghazwan  Fadhil" [ghazwan_fadhil---yahoo.co.uk]
I am doing geometry optimization using Gaussian 09 software to a fused 
cyclic rings with chlorine atom on fused carbon atom. The DFT with 6-311G 
dp(++) and ab initio give optimized structure with no negative frequency 
but the chlorine atom got elongated and became unbonded. However, GO with 
semi-empirical PM 6 does not give  such elongation and un-bonded chlorine 
is not observed, i.e. normal result obtained. I request explanation and a 
suggestion to overcome this problem.


From owner-chemistry@ccl.net Sat Jun 30 15:00:01 2018
From: "Alfy Benny alfy16]![iisertvm.ac.in" <owner-chemistry=-=server.ccl.net>
To: CCL
Subject: CCL: SAPT (Symmetry Adapted Perturbation Theory) calcualtions gets killed
Message-Id: <-53365-180630065204-22715-23YxUK1RSLbJBE9almMgnA=-=server.ccl.net>
X-Original-From: "Alfy   Benny" <alfy16#%#iisertvm.ac.in>
Date: Sat, 30 Jun 2018 06:51:51 -0400


Sent to CCL by: "Alfy   Benny" [alfy16###iisertvm.ac.in]
I tried to do SAPT(0) calculations for a set of dimers using the jun-cc-pVDZ basis set with 8000 MB memory. But the calculations are getting killed without any errors for some of my dimers (dimers are composed of similar monomers). All are terminated when the calculations proceeds to ITERATION. The monomer is a Poly Aromatic Hydrocarbon with 42 carbons. The similar molecule substituted with 4 Nitrogen successfully completed the SAPT(0) calculation for its dimer. Please help.