本文目录
- Quasi-Atomic Molecular Orbitals是什么意思
- degenerated molecular orbitals是什么意思
- 原子轨道的主量子数，角量子数和磁量子数
- 为什么ms软件进行castep分析时点orbitals不能import
Quasi-Atomic Molecular Orbitals是什么意思
翻译：准原子分子轨道微观轨道与宏观轨道的意义是不同的。两者都是指粒子运行的区域，但宏观轨道一般都是光滑的曲线，而微观轨道则往往是指空间的一定范围（严格来说，不论是哪个微粒的轨道其实都是分布于全空间的，但一般它在绝大部分空间出现的概率都极小，而它经常出现的空间区域就是它的轨道），这个范围的边界是模糊的，所以也常用“云”这个概念来替代“轨道”。在高中化学中遇到的“电子云”其实就是“电子轨道”，两个名称，一个实体！ 原子轨道和分子轨道其实就是指其中的电子的轨道，这是一种约定俗成的简称，实际应为“原子中的电子轨道”与“分子中的电子轨道”。 单独一个原子时，它的电子都围绕着该原子的原子核运动，这样形成的电子轨道就是原子轨道。当若干个原子组成分子时，原子的内层电子基本上还是围绕这个原子的原子核运动，它们的电子轨道也变化不大；但外层的电子现在就可以在更大的范围甚至是整个分子的范围内运动了，这样原来的由这些外层电子构成的原子轨道就消失了，它们重组成统一的属于整个分子的新轨道，此即分子轨道。 分子轨道往往比原子轨道复杂的多，因而出现了极多密集的能级。这些能级分成若干组，组与组之间的能级差别较大，而组内各能级的差别很小，看起来像是连成了一片，这就形成了一个能带。每一组能级就是一个能带。 http://baike.baidu.com/view/152265.htm http://baike.baidu.com/view/883030.htm
degenerated molecular orbitals是什么意思
degenerated molecular orbitals的中文翻译： degenerated molecular orbitals 退化分子轨道 -------------------------------如有疑问，可继续追问，如果满意，请采纳，谢谢。
原子轨道的主量子数，角量子数和磁量子数
The principal quantum number（主量子数）The azimuthal quantum number（角量子数）The magnetic quantum number（磁量子数） The spin projection quantum number（自旋量子数） the electron shell, or energy level. The value of ranges from 1 to “n“, where “n“ is the shell containing the outermost electron of that atom. For example, in cesium (Cs), the outermost valence electron is in the shell with energy level 6, so an electron in cesium can have an value from 1 to 6. the subshell (0 = s orbital, 1 = p orbital, 2 = d orbital, 3 = f orbital, etc.). The value of ranges from 0 to . This is because the first p orbital (l=1) appears in the second electron shell (n=2), the first d orbital (l=2) appears in the third shell (n=3), and so on. A quantum number beginning in 3,0,... describes an electron in the s orbital of the third electron shell of an atom. the specific orbital (or “cloud“) within that subshell.* The values of range from to . The s subshell (l=0) contains only one orbital, and therefore the ml of an electron in an s subshell will always be 0. The p subshell (l=1) contains three orbitals (in some systems, depicted as three “dumbbell-shaped“ clouds), so the ml of an electron in a p subshell will be -1, 0, or 1. The d subshell (l=2) contains five orbitals, with ml values of -2,-1,0,1, and 2. the spin of the electron within that orbital. since atoms and electrons are in a state of constant motion, there is no universal fixed value for ml and ms values. Therefore, the ml and ms values are defined somewhat arbitrarily. The only requirement is that the naming schematic used within a particular set of calculations or descriptions must be consistent (e.g. the orbital occupied by the first electron in a p subshell could be described as ml=-1 or ml=0, or ml=1, but the ml value of the other electron in that orbital must be the same, and the ml assigned to electrons in other orbitals must be different). The principal quantum number（主量子数） (n = 1, 2, 3, 4 ...) denotes the eigenvalue of H with the J2 part removed. This number therefore has a dependence only on the distance between the electron and the nucleus (i.e., the radial coordinate, r). The average distance increases with n, and hence quantum states with different principal quantum numbers are said to belong to different shells. The azimuthal quantum number（角量子数） (l = 0, 1 ... n�6�11) (also known as the angular quantum number or orbital quantum number) gives the orbital angular momentum through the relation . In chemistry, this quantum number is very important, since it specifies the shape of an atomic orbital and strongly influences chemical bonds and bond angles. In some contexts, l=0 is called an s orbital, l=1 a p orbital, l=2 a d orbital, and l=3 an f orbital. The magnetic quantum number（磁量子数） (ml = �6�1l, �6�1l+1 ... 0 ... l�6�11, l) yields the projection of the orbital angular momentum along a specified axis. . The spin projection quantum number（自旋量子数） (ms = �6�11/2 or +1/2), is the intrinsic angular momentum of the electron or nucleon. This is the projection of the spin s=1/2 along the specified axis. When one takes the spin-orbit interaction into consideration, the l-, m- and s-operators no longer commute with the Hamiltonian, and their eigenvalues therefore change over time. Thus another set of quantum numbers should be used. This set includesThe total angular momentum quantum number (j = 1/2,3/2 ... n�6�11/2) gives the total angular momentum through the relation .The projection of the total angular momentum along a specified axis (mj = -j,-j+1... j), which is analogous to m, and satisfies mj = ml + ms.Parity. This is the eigenvalue under reflection, and is positive (i.e. +1) for states which came from even l and negative (i.e. -1) for states which came from odd l. The former is also known as even parity and the latter as odd parityFor example, consider the following eight states, defined by their quantum numbers:n = 2, l = 1, ml = 1, ms = +1/2n = 2, l = 1, ml = 1, ms = -1/2n = 2, l = 1, ml = 0, ms = +1/2n = 2, l = 1, ml = 0, ms = -1/2n = 2, l = 1, ml = -1, ms = +1/2n = 2, l = 1, ml = -1, ms = -1/2n = 2, l = 0, ml = 0, ms = +1/2n = 2, l = 0, ml = 0, ms = -1/2The quantum states in the system can be described as linear combination of these eight states. However, in the presence of spin-orbit interaction, if one wants to describe the same system by eight states which are eigenvectors of the Hamiltonian (i.e. each represents a state which does not mix with others over time), we should consider the following eight states:j = 3/2, mj = 3/2, odd parity (coming from state (1) above)j = 3/2, mj = 1/2, odd parity (coming from states (2) and (3) above)j = 3/2, mj = -1/2, odd parity (coming from states (4) and (5) above)j = 3/2, mj = -3/2, odd parity (coming from state (6))j = 1/2, mj = 1/2, odd parity (coming from states (2) and (3) above)j = 1/2, mj = -1/2, odd parity (coming from states (4) and (5) above)j = 1/2, mj = 1/2, even parity (coming from state (7) above)j = 1/2, mj = -1/2, even parity (coming from state (8) above)
为什么ms软件进行castep分析时点orbitals不能import
为什么ms软件进行castep分析时点orbitals不能importHOMO是能量值为零,而LUMO 就是它的上一个轨道.CASTEP用以价带的最高点为能量零点,也就是HOMO轨道.这个说法值得商榷吧,castep和Dmol3都是强行把VBM和Fermi level都设置为零,但是这只是在band structure的计算里面,但是dmol3的输出文件里面给出的Fermi level事实上并不是零,而一般计算出来的HOMO和LUMO也都不是在零点.那么,在castep里面不能把castep强行设置的零点当做真实的吧?还是castep这点与dmol3不同,就把VBM和Fermi level都认定为零点了?其实VBM和CBM都只是一个相对的大小值,大小完全取决于选择的参照点,只是它们之间的差值也就是band gap是固定的,只是不敢确定在castep中,怎样判断具体的HOMO和LUMO.yjmaxpayne(站内联系TA)基本同意版主的说法, 但是我建议最好再结合占据数情况进行分析.viplaji006(站内联系TA)您说的非常有道理的,在真正的分析数据时这些都是要考虑的.我在用CASTEP计算富勒烯分子如 C60 C70 C84的时候,发现CASTEP得出的结果都是把HOMO定为能量0点的,（根据轨道的简并性,可以简单的认出HOMO轨道）.这个说法值得商榷吧,castep和Dmol3都是强行把VBM和Fermi level都设置为零,但是这只是在band structure的计算里面,但是dmol3的输出文件里面给出的Fermi level事实上并不是零,而一般计算出来的HOMO和LUMO也都 ... qgqgrm(站内联系TA)个人认为可以从基本概念上来理解.Homo和Lumo是指最高和最低电子占据轨道,只与费米能级的相对位置有关,而费米能级是指电子占据几率是50%的能级,低于此能级轨道占据几率迅速增大,可认为是满带,而高于此能级占据几率迅速减小,可认为是空带.在CASTEP中费米能级非常。