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hopedream

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[求助] 相同原子数,不同的构想,如何比较稳定性 已有1人参与

如题:相同原子数,不同的构想,我优化这三种结构后,得到总的能量如下:
-5708.1340741Ha,-5708.0693263Ha,-5708.0154604Ha
是不是能量越负越稳定呢?

还有不知道这样做正确吗,上面的能量还需要进行能量优化吗,再比较其能量的大小?
我总是不知道啥时候只几何优化,啥时候能量优化,啥时候先几何优化再能量优化
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Jasminer

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【答案】应助回帖

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感谢参与,应助指数 +1
hopedream: 金币+2, 有帮助 2016-10-15 19:05:15
1、是
2、就是几何优化,没有能量优化这种叫法(可能是非正规的口头叫法)
2楼2016-09-18 15:05:30
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小范范1989

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It doesn't matter how slow you are, as long as you're determined to get there, you'll get there.
3楼2016-09-18 15:16:29
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hopedream

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引用回帖:
2楼: Originally posted by Jasminer at 2016-09-18 15:05:30
1、是
2、就是几何优化,没有能量优化这种叫法(可能是非正规的口头叫法)

我是问的是:一般不是有Opt和energy吗,我想知道某个结构的能量,是看进行Opt优化后的能量,还是经过Opt优化后再进行一次energy优化得出的能量?非常谢谢你的热心的解答
4楼2016-09-18 16:16:25
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hopedream

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引用回帖:
3楼: Originally posted by 小范范1989 at 2016-09-18 15:16:29
http://bbs.keinsci.com/forum.php?mod=viewthread&tid=600
http://bbs.keinsci.com/forum.php?mod=viewthread&tid=1137
http://bbs.keinsci.com/forum.php?mod=viewthread&tid=1207
http://bbs.kei ...

我只是想知道构建的结构是否稳定,比如相同的原子数目,就是排布的不同而已。我已经看了你的帖子。其实HOMO_LUMO gap 是可以说明稳定性的。
The kinetic stability of a molecule has a crucial influence on
its synthetic accessibility and isolability. By kinetic stability we
mean stability with respect to the activated complex of any
further chemical reaction.
1 In order for a molecule to be isolable,
it must be not only thermodynamically but also kinetically
stable. Thermodynamic stability can easily be estimated ex-
perimentally and/or computationally. However, it is very
difficult to estimate the degree of kinetic stability because it is
related to innumerable chemical reactions.
The highest occupied molecular orbital (HOMO) lowest
unoccupied molecular orbital (LUMO) energy separation has
been used as a simple indicator of kinetic stability.
1 11 A large
HOMO LUMO gap implies high kinetic stability and low
chemical reactivity, because it is energetically unfavorable to
add electrons to a high-lying LUMO, to extract electrons from
a low-lying HOMO, and so to form the activated complex of
any potential reaction.
1 Pearson pointed out that the HOMO
LUMO gap represents the chemical hardness of a molecule.
3,6,7,10
Zhou and Parr discussed the chemical reactivity of cyclic
conjugated systems using the HOMO LUMO gaps of the
reactant and the transition state.
8
5楼2016-09-18 16:54:14
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