英语翻译Natural Bond Orbitals (NBOs) are localized few-center or

英语翻译
Natural Bond Orbitals (NBOs) are localized few-center orbitals ("few" meaning typically 1 or 2,but occasionally more) that describe the Lewis-like molecular bonding pattern of electron pairs (or of individual electrons in the open-shell case) in optimally compact form.More precisely,NBOs are an orthonormal set of localized "maximum occupancy" orbitals whose leading N/2 members (or N members in the open-shell case) give the most accurate possible Lewis-like description of the total N-electron density.
Neither the form of the bonding hybrids nor the locations of localized bonds and lone pairs are pre-determined.Rather,the NBO program searches over all possible ways of drawing the bonds and lone pairs for the variationally optimal bonding pattern that places maximum occupancy (highest percentage of the total electron density) in the leading N/2 "Lewis-type" NBOs (typically >99.9% for common organic molecules).The Lewis-type NBOs determine the localized Natural Lewis Structure (NLS) representation of the wavefunction,while the remaining "non-Lewis"-type NBOs complete the span of the basis and describe the residual "delocalization effects" (i.e.,departures from a single localized Lewis structure).Thus,NBOs provide a valence bond-type description of the wavefunction,closely linked to classical Lewis structure concepts.As in the NAO case,the only input to the NBO algorithms is the molecular wavefunction Ψ (through its first-order reduced density operator Γ),so the numerically determined Lewis structure representation is "natural" to Ψ itself.

自然键轨道（ NBOs ）是描叙路易斯共用电子对结构（或孤对电子）的紧凑的最佳定域键（典型的中心原子为1到2个,但偶尔超过2）形式.更确切地说,是一个“最大占用”定域键轨道的规范化正交集,其主要的N/2个键（或孤对电子的N个键）给出了最精确合适的路易斯结构所描叙的所有N个键的电子密度.
无论是杂化轨道,还是定域轨道和孤对电子都不是预先确定的.相反,NBO程序将在主要的N/2个自然轨道中搜索对于变化键型的所有可能的键和孤对电子的画法,使轨道的占有率达到最大（总的电子密度达到最大)(对有代表性的>99.9%的一般有机分子验证过).路易斯型自然键轨道测定波函数所表现出的定域自然键结构,而剩余的“非刘易斯”型自然键轨道则完整的说明了离域的基础,并说明了剩余的“离域效应”（也就是说,违反了单一的路易斯定域结构的部分）.因此,自然键轨道提供了描述波函数的“原子价”,密切联系着经典路易斯结构的概念.如“NAO”情况下,只需输入NBO算法的分子波函数Ψ（通过它的第一级约化的密度算符Γ）,那么由数值决定的路易斯结构就会给出 Ψ的最“自然”的描叙.
这应该是介绍NBO软件的吧.“NAO”我译不出来.有个别词语是根据化学知识加上去的.感觉这篇文章和一般的化学文献语言习惯有点不同,译起来稍麻烦.