From owner-chemistry@ccl.net Tue Mar 25 23:38:00 2014 From: "Hyungjun Kim hyungjun96|,|gmail.com" To: CCL Subject: CCL: Modifying alpha, beta in CAM-B3LYP using IOp Message-Id: <-49870-140325233703-17142-y2BiyqTsar6py5/6kGAjFA#,#server.ccl.net> X-Original-From: "Hyungjun Kim" Date: Tue, 25 Mar 2014 23:37:02 -0400 Sent to CCL by: "Hyungjun Kim" [hyungjun96|*|gmail.com] Dear CCL subscribers, 1. I would like to change alpha, beta parameters in CAM-B3LYP. I find that IOp(3/119) is the option related to the coefficient of short/long range HF exchange. When I use IOp(3/119=0460001800) to compare the results with default CAM- B3LYP, I get the "cShort=***** and cLong=0.4600". But the total energy is same. This is my first question. The contribution of "cShort" is not included? 2. After several tries, I realized that even though IOp(3/119) has (3/119=MMMMMNNNNN) format, I can't separate short and long range coefficient. I want to modify the coefficient alpha and beta individually. Does any body have idea about this? 3. Final question is the structure of CAM-B3LYP. The default composition of CAM-B3LYP output is like below. **** HFx wShort= 0.000000 wLong= 0.330000 cFull= 0.190000 cShort= 0.000000 cLong= 0.460000 DFx wShort= 0.000000 wLong= 0.330000 cFull= 0.190000 cShort= 0.000000 cLong= 0.460000 **** When I find the original CAM-B3LYP paper, the alpha=0.19 and beta=0.46 is recommended. Then I think the contribution of DFT should be like cFull=0.35, cShort=0.65 and cLong=0.00. Any comments will be appreciated.