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lhjxgy銀蟲 (正式寫手)
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[求助]
計算反鐵磁
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| 我是學(xué)配位化學(xué)的,近來合成了五個錳的配合物,有雙核,四核,六核,統(tǒng)一錳鏈,交替錳鏈SBU的化合物,做了磁性,但是我想通過量化計算計算它們的理論J值,從而比較一下它們磁性傳遞情況,我應(yīng)該從哪入手? |
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對于線性的構(gòu)型了解的不多,但對反鐵磁的計算,可以參考G09手冊以下部分: Antiferromagnetic coupling. Here is an example of a fragment guess job. The first step generates guesses for each one of the fragments, and then combines them together into a guess for the SCF on the full molecule. The second step reads in that guess for a subsequent calculation. The charge and multiplicity line has the overall molecular charge and multiplicity first, followed by those for each fragment. This example is Fe2S2 + 4 S-R ligands, where R is a phenyl group. It is a singlet with an overall charge of -2. The guess does each bare sulfur as S(2-) closed-shell (fragments 2 and 4), the two irons as Fe(3+) sextets antiferromagnetically coupled (fragments 1 and 3, with 1 being alpha-spin and 3 beta-spin), and each of the S-R fragments (5-8) as closed-shell singlet anions. 需要注意的是, %chk=FragGuess %mem=64mw #P UBP86/6-311G(d) Guess=(Fragment=8,Only) Pop=None 第一步只做初猜,第二步在家優(yōu)化或其他性質(zhì)計算的關(guān)鍵詞。有時候為了得到你想要的構(gòu)型,你只能選比較小的基組算,收斂后慢慢往上加基組。 如果用G03,高斯網(wǎng)站上介紹過一種方法,覺得比較復(fù)雜。一個簡單的方法是,先收斂到多重度為3的構(gòu)型,然后再把多重度改為1繼續(xù)算,很快能得到反鐵磁的構(gòu)型。如果仍有困難,計算量不大的話,把高自旋的構(gòu)型的結(jié)果拿出來,再把多重度改為1繼續(xù)算,應(yīng)該會有好的結(jié)果。 沒算過J值,J值得計算可以參考附件的文獻(xiàn)! 反鐵磁.rar http://kuai.xunlei.com/d/GSJVPILVWETJ?p=130497 |
鐵桿木蟲 (著名寫手)
鐵桿木蟲 (著名寫手)
鐵桿木蟲 (著名寫手)
鐵桿木蟲 (著名寫手)
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