CCL:G: requirements in calculating charged species with gaussian

From: "Daorina Sharnod" <rina.dao=gmail.com>
Subject: CCL:G: requirements in calculating charged species with gaussian
Date: Sat, 1 Jun 2013 14:09:28 -0400

 Sent to CCL by: "Daorina  Sharnod" [rina.dao:_:gmail.com]
 Dear all!
 I have been calculating a salt with a two valence cation baring two pyridinium
 cations and two [BF4-]s.The question arises that whether the method for
 calculating neutral compounds is suitable for ionic species. For the parent
 compound without the pyridine substituent,both a 6-31g(d,p) and high basis set
 calculation(6-311++G(d,p)for single point energy and 6-311+G(d)for zero-point
 energy correction) in geometric optimization and transition state identification
 of hydrogen atom transfer from toluene to the compound are carried out using
 b3lyp functional. The calculated activation energies are not so different
 between the one in 6-31G(d,p) and in high basis set.
 So basicly,the problem is can a b3lyp/6-31G(d,p) method still be good for
 optimization and reaction barrier calculation on the salt? Should there be any
 concern in the functional and basis set if a highly charged species is to be
 calculated in gaussian?
 I would be grateful if anyone offers a suggestion!
 Best regards!
 sincerely
 Daorina