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嗯嗯，明白了，谢谢，那什么情况下可以接受呢？整段话如下：Theoretical calculations were performed with the Gaussian09 program suite using a supercomputer (KISTI, IBM).1 All calculations were carried out using the density functional theory (DFT) method with Becke’s three-parameter hybrid exchange functionals and the Lee-Yang-Parr correlation functional (B3LYP) employing the 6-31G(d,p) basis set for all atoms.2 To reduce the computation cost, the N-alkyl chains of the models of nPer-CN are replaced by methyl groups. Singlet biradical character was estimated using a CASSCF(2,2) method in the RB3LYP optimized geometry, and using a symmetry-broken UB3LYP/6-31G** method along with geometry optimization. To compare the closed-shell (CS), singlet biradical (SB), and triplet biradical (TB) energies, the each geometry was optimized by using restricted, broken symmetry, and unrestricted triplet formalisms (B3LYP/6-31G(d,p)), respectively. Frequency analysis verified that all geometries of nPer-CN obtained in these optimizations do not contain any negative frequencies. The intramolecular exchange interaction (JkB-1) was calculated according to the following equation; JkB –1 = (ESB – ETB)/(<S2>TB – <S2>SB), where EX and <S2> X denote the total energy and total spin angular momentum of the spin state X, respectively.3
The singlet biradical index y was determined on the basis of the LUMO occupation number. A perfect biradical is characterized by occupation numbers of 1.0 in HOMO and LUMO (i.e. y = 100%), whereas a perfect closed-shell molecule possesses occupation numbers of 2.0 and 0.0 in HOMO and LUMO (i.e. y = 0%), respectively.4 The global ring centers for the NICS(1) values were designated at the non-weighted mean centers of the rings. The NICS(1)zz means total MO contribution to the zz component of the NICS tensor.5 The NICS value was obtained with gauge independent atomic orbital (GIAO) method based on the optimized geometries. To simulate the ground-state absorption spectra, the time-dependent (TD) DFT calculation was employed with UB3LYP/6-31G(d,p) level. 这个问什么是可以的呢？ |
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发表于 Post on 2016-3-19 10:36:45
，Thank you
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