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小弟初学gamess，希望利用其中的sf-tddft寻找势能曲线的圆锥交叉，参考的文献为J. Phys. Chem. A, 2009, 113 (46), pp 12749–12753,该文利用sf-tddft研究了乙烯S1和S0的CI,可是我没办法重复出文献中的结果。以下是我的输入文件：
$CONTRL SCFTYP=UHF DFTTYP=BHHLYP TDDFT=SPNFLP MULT=3 RUNTYP=CONICAL
EXETYP=RUN MAXIT=200 $END
$SYSTEM TIMLIM=525600 MEMORY=6200000 $END
$BASIS GBASIS=N31 NGAUSS=6 NDFUNC=1 NPFUNC=1 $END
$guess guess=huckel $end
$tddft nstate=5 iroot=1 tammd=.true. $end
$CONICL OPTTYP=PENALTY IXROOT(1)=1,4 $END
$STATPT NSTEP=1000 $END
$scf dirscf=.t. $end
$DATA
Title
C1
C 6.0 0.0000000000 0.0000000000 -0.6635189607
C 6.0 0.0000000000 0.0000000000 0.6635189607
H 1.0 0.9162439386 0.0000000000 -1.2297557119
H 1.0 -0.9162439386 0.0000000000 -1.2297557119
H 1.0 0.9162439386 0.0000000000 1.2297557119
H 1.0 -0.9162439386 0.0000000000 1.2297557119
$END
其中乙烯的结构是文献给的基态结构，IXROOT(1)=1,4是因为1，4分别对应S0 和S1，可是我的计算结果和文献对不上，只能得到一个两个CC键不断增长CH2相互远离的结构。
文献中计算细节的描述如下：
The BHHLYP hybrid functional (50% Hartree-Fock plus 50% Becke exchange34 with Lee-Yang-Parr correlation35) was employed in this work because SFDFT benchmark calculations suggest better performance with a larger fraction of Hartree-Fock exchange.24 The basis sets employed were 6-31G(d,p) and aug-cc-pVTZ.36,37 The former was used in the MS-CASPT2 study of ref 21 and the latter in the MR-CI calculations in ref 15. The BroydenFletcher-Goldfarb-Shannon (BFGS) quasi-Newton scheme was adopted to minimize the objective function in eq 3. The same optimization criteria, thresholds, and parameters were used as discussed in ref 21, where three criteria were considered to achieve convergence, the change in the objective function f and the parallel and perpendicular components of the gradient of f with respect to the direction of the gradient vector of the penalty (the second term in eq 3). They were minimized simultaneously to be lower than a given threshold. No symmetry constraint was applied during the CI optimizations.
请各位前辈帮忙看一下我的问题究竟出在哪里，另外想问大家IXROOT后边括号里的数字有什么意义，手册里没有找到。还有就是通过观察输出文件我发现在中间步骤（NSEARCH）中第一和第四激发态已经不再对应S0和S1，并且出现了很多单重态和三重态混合的激发态（S SQUARE=1）请问这种情况怎样解释和解决。
另外附上了输出文件，请各位斧正。
问题很多，麻烦大家了，万分感谢！
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发表于 Post on 2015-6-19 02:06:35
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发表于 Post on 2015-9-15 14:31:09
