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[求助]
VASP计算出来的BLOCH 波函数的相位问题。 已有1人参与
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以下是我发给VASP-support 的邮件 Dear Sir or Madam, Recently, I tried to output the wavefunction Un (k, r) ( n is the energy band, k is the crystal momentum) calculated by VASP. As a complex wave function, Un(k, r) should be continuous in respect to k and r, physically. While, I found that when r is fixed, Un(k, r) is not continuous in respect to k. I mean, although the absolute value of Un(k, r) is continuous in respect to k, the phase of Un(k, r) is not (as shown in the figure below). I checked the self-consistency scheme of VASP, I saw that the wave function is initialized using a random number generator, and the convergence criteria is related to energy. I wonder it is the random number generator that introduces random phases into the wavefunction Un(k, r) at last. And, this random phase won’t influence the convergence standard. Can you tell me whether what I think is right? Anyway, I think the phases of the wavefunction are very important physically. So, I want to get some advices from vasp-support about how to deal with the random phases. 大概意思就是BLOCH 波函数Un (k, r) 是个复数，但是VASP计算出来的波函数的相位对晶格动量K 不是连续的，这在物理上是不对的。 但是VASP给我回复的邮件好敷衍，就两句话。 please note that WAVECAR only contains the wavefunctions COEFFICIENTS, not the wavefuction itself. the random number generator initiates some starting values of these coefficients。 it has nothing to do with random phase. 他回复的东西完全没用嘛。有没有人比较精通VASP计算原理的，来说说这个random的phase到底来自于计算的哪些步骤。我觉得可能是来自于初始赋值以及迭代过程中矩阵对角化。 如何才能解决这个随机相位的问题呢？ |
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2楼2017-03-04 07:28:27
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3楼2017-03-04 16:39:18