There are reasons to consider quantum calculations to be necessary for ion channels, for two types of reasons. The calculations must account for charge transfer, and the possible switching of hydrogen bonds, which are very difficult with classical force fields. Without understanding charge transfer and hydrogen bonding in detail, the channel cannot be understood. Thus, although classical approximations to the correct force fields are possible, they are unable to reproduce at least some details of the behavior of a system that has atomic scale. However, there is a second class of effects that is essentially quantum mechanical. There are two types of such phenomena: exchange and correlation energies, which have no classical analogues, and tunneling. Tunneling, an intrinsically quantum phenomenon, may well play a critical role in initiating a proton cascade critical to gating. As there is no classical analogue of tunneling, this cannot be approximated classically. Finally, there are energy terms, exchange and correlation energy, whose values can be approximated classically, but these approximations must be subsumed within classical terms, and as a result, will not have the correct dependence on interatomic distances. Charge transfer, and tunneling, require quantum calculations for ion channels. Some results of quantum calculations are shown.

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离子通道的量子计算：为什么它们比经典计算更有用？它们对于哪些过程至关重要？

由于两种原因，有理由认为对离子通道进行量子计算是必要的。这些计算必须考虑到电荷转移以及氢键的可能转换，这对于经典力场而言是非常困难的。如果不详细了解电荷转移和氢键，则无法理解该通道。因此，尽管可以对正确的力场进行经典近似，但是它们无法再现具有原子尺度的系统的行为的至少某些细节。然而，存在第二类效应，其基本上是量子力学的。这种现象有两种类型：交换能和相关能（没有经典的类似物）和隧道效应。隧道效应，一种固有的量子现象，可能在引发对门控至关重要的质子级联中起关键作用。由于没有经典的隧道模拟，因此无法经典地近似。最后，存在能量项，交换和相关能量，其值可以经典地近似，但是这些近似值必须包含在经典项内，因此，它们对原子间距离的正确依赖性不大。电荷转移和隧穿需要对离子通道进行量子计算。显示了量子计算的一些结果。结果，将不会正确依赖原子间距离。电荷转移和隧穿需要对离子通道进行量子计算。显示了量子计算的一些结果。结果，将不会正确依赖原子间距离。电荷转移和隧穿需要对离子通道进行量子计算。显示了量子计算的一些结果。