本文针对软件版本为AMS2019.3(旧版不支持),AMS2020以后的版本请参考链接:FDE方法计算分子间电子、空穴转移,相关在位能site energy、激发能Excitation energy的计算
本功能可以计算分子之间电子或空穴转移的过程中的能垒,具体参考: ADF厂商提供英文例子
FDE方法之所以更精确,因为它考虑到了两个分子之间由于电子、空穴的转移,引起的各自的电子态的弛豫(因此,在两次带电的FDE计算过程中,计算了几次单点,这实际上是一个弛豫过程:冻结A的密度,计算B,然后冻结B的密度计算A……)
下面我们简略地讲一下这个例子。在adf201x.10x/examples/adf/ElectronTransfer_FDE_H文件夹内也有这个例子。本例是以水分子之间传递空穴(正电荷)为例。包括如下几个步骤:
理论上的参考文献:
M. Pavanello and J. Neugebauer, Modelling charge transfer reactions with the frozen density embedding formalism, Journal of Chemical Physics 135, 234103 (2011)
M. Pavanello, T. Van Voorhis, L. Visscher, and J. Neugebauer, An accurate and linear-scaling method for calculating charge-transfer excitation energies and diabatic couplings, Journal of Chemical Physics 138, 054101 (2013)
#!/bin/sh $ADFBIN/adf<< eor SYMMETRY NOSYM XC GGA PW91 END ATOMS O 0.0000000000 0.0000000000 0.0000000000 H -0.9358409558 .2646136961 0.0000000000 H -0.0304663436 -0.9828924420 0.0000000000 END NumericalQuality good BASIS Type TZP Core None END END INPUT eor mv TAPE21 t21.iso.rho1 $ADFBIN/adf<< eor SYMMETRY NOSYM XC GGA PW91 END ATOMS O 0.0000000000 -2.9053396088 0.0000000000 H -0.4092227596 -3.3374838250 -0.7701260000 H -0.4092227596 -3.3374838250 0.7701260000 END NumericalQuality good BASIS Type TZP Core None END END INPUT eor mv TAPE21 t21.iso.rho2
说明,两个中性分子的计算,与一般的单点计算相比并没有特别之处。
$ADFBIN/adf << eor SYMMETRY NOSYM XC GGA PW91 END CHARGE 1 1 UNRESTRICTED FRAGMENTS rho1 t21.iso.rho1 rho2 t21.iso.rho2 type=fde END ATOMS O 0.0000000000 0.0000000000 0.0000000000 f=rho1 H -0.9358409558 .2646136961 0.0000000000 f=rho1 H -0.0304663436 -0.9828924420 0.0000000000 f=rho1 O 0.0000000000 -2.9053396088 0.0000000000 f=rho2 H -0.4092227596 -3.3374838250 -0.7701260000 f=rho2 H -0.4092227596 -3.3374838250 0.7701260000 f=rho2 END NumericalQuality good ALLOW PARTIALSUPERFRAGS FDE PW91K GGAPOTXFD pw91x GGAPOTCFD pw91c END END INPUT eor mv TAPE21 t21.emb.rho1 $ADFBIN/adf<< eor SYMMETRY NOSYM XC GGA PW91 END FRAGMENTS rho1 t21.emb.rho1 subfrag=active type=fde rho2 t21.iso.rho2 END ATOMS O 0.0000000000 0.0000000000 0.0000000000 f=rho1 H -0.9358409558 .2646136961 0.0000000000 f=rho1 H -0.0304663436 -0.9828924420 0.0000000000 f=rho1 O 0.0000000000 -2.9053396088 0.0000000000 f=rho2 H -0.4092227596 -3.3374838250 -0.7701260000 f=rho2 H -0.4092227596 -3.3374838250 0.7701260000 f=rho2 END NumericalQuality good ALLOW PARTIALSUPERFRAGS FDE PW91K GGAPOTXFD pw91x GGAPOTCFD pw91c END END INPUT eor mv TAPE21 t21.emb.rho2 $ADFBIN/adf<< eor SYMMETRY NOSYM XC GGA PW91 END CHARGE 1 1 UNRESTRICTED FRAGMENTS rho1 t21.iso.rho1 rho2 t21.emb.rho2 subfrag=active type=fde END restart t21.emb.rho1 ATOMS O 0.0000000000 0.0000000000 0.0000000000 f=rho1 H -0.9358409558 .2646136961 0.0000000000 f=rho1 H -0.0304663436 -0.9828924420 0.0000000000 f=rho1 O 0.0000000000 -2.9053396088 0.0000000000 f=rho2 H -0.4092227596 -3.3374838250 -0.7701260000 f=rho2 H -0.4092227596 -3.3374838250 0.7701260000 f=rho2 END NumericalQuality good ALLOW PARTIALSUPERFRAGS FDE PW91K GGAPOTXFD pw91x GGAPOTCFD pw91c END END INPUT eor mv TAPE21 t21.emb.rho1 $ADFBIN/adf<< eor SYMMETRY NOSYM XC GGA PW91 END FRAGMENTS rho1 t21.emb.rho1 subfrag=active type=fde rho2 t21.emb.rho2 subfrag=active END ATOMS O 0.0000000000 0.0000000000 0.0000000000 f=rho1 H -0.9358409558 .2646136961 0.0000000000 f=rho1 H -0.0304663436 -0.9828924420 0.0000000000 f=rho1 O 0.0000000000 -2.9053396088 0.0000000000 f=rho2 H -0.4092227596 -3.3374838250 -0.7701260000 f=rho2 H -0.4092227596 -3.3374838250 0.7701260000 f=rho2 END NumericalQuality good ALLOW PARTIALSUPERFRAGS FDE PW91K GGAPOTXFD pw91x GGAPOTCFD pw91c END END INPUT eor mv TAPE21 t21.emb.rho2 mv t21.emb.rho1 fragA1.t21 mv t21.emb.rho2 fragA2.t21
说明:
本计算与前者类似。使用FDE方法,得到了精确的第一个分子中性片段(fragB1.t21)、第二分子带电片段的电子结构(fragB2.t21)。具体文件参考原文件。类似地,对于简并能级的体系,用户可以在这里对带电片段,指定占据方式,从而达到限定电子、空穴通过哪个简并轨道进行hopping
注意,上面两个计算,分别得到的片段的文件名必须是fragA1.t21、fragA2.t21、fragB1.t21、fragB2.t21。
$ADFBIN/adf -n 1 << eor FRAGMENTS rho1 t21.iso.rho1 rho2 t21.iso.rho2 END ATOMS O 0.0000000000 0.0000000000 0.0000000000 f=rho1 H -0.9358409558 .2646136961 0.0000000000 f=rho1 H -0.0304663436 -0.9828924420 0.0000000000 f=rho1 O 0.0000000000 -2.9053396088 0.0000000000 f=rho2 H -0.4092227596 -3.3374838250 -0.7701260000 f=rho2 H -0.4092227596 -3.3374838250 0.7701260000 f=rho2 END NumericalQuality good CHARGE 1 1 UNRESTRICTED XC GGA PW91 END SYMMETRY nosym SCF iterations 0 END ELECTRONTRANSFER numfrag 2 END END INPUT eor
注意: