CCL: SV: TDDFT (CAM-B3LYP) oscillator strength too high



 Sent to CCL by: Jens Spanget-Larsen [spanget[]ruc.dk]
 Dear Micaela,
 why do you think that an oscillator strength f = 2.7 is unphysical? This is
 certainly a large value, but it is not necessarily unreasonable. With
 TD-PBE1PBE/6-31+G*, we obtained f = 2.2  for the first optically allowed
 electronic transition in the D2d conformation of diphenyldiacetylene, see
 Thulstrup et al., PCCP 13, 16168-16174 (2011).
 Jens >--<
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 Fra: owner-chemistry+spanget==ruc.dk[#]ccl.net
 [owner-chemistry+spanget==ruc.dk[#]ccl.net] p&#229; vegne af micaela matta
 micaela.matta2 .. unibo.it [owner-chemistry[#]ccl.net]
 Sendt: 10. december 2013 17:05
 Til: Jens Spanget-Larsen
 Emne: CCL: TDDFT (CAM-B3LYP) oscillator strength too high
 Sent to CCL by: "micaela  matta" [micaela.matta2 .. unibo.it]
 Dear CCL suscribers,
 I am running TD-DFT calculations on an organic molecule at level CAM-BLYP/6-
 311G*. The first excited state has the correct energy compared to experimental
 results, but I obtained an unphysical f=2.7206!! How can I make sense of this
 result?
 Thanks
 Micaelahttp://www.ccl.net/cgi-bin/ccl/send_ccl_messagehttp-:-//www.ccl.net/chemistry/sub_unsub.shtmlhttp-:-//www.ccl.net/spammers.txt