Transition State - Locating Transition States By Computational Chemistry

Locating Transition States By Computational Chemistry

Transition state structures can be determined by searching for first-order saddle points on the potential energy surface (PES). Such a saddle point is a point where there is a minimum in all dimensions but one. Almost all quantum-chemical methods (DFT, MP2 etc.) can be used to find transition states. However, locating them is often difficult and there is no method guaranteed to find the right transition state. There are many different methods of searching for transition states and different quantum chemistry program packages include different ones. Many methods of locating transition states also aim to find the minimum energy pathway (MEP) along the PES. Each method has its advantages and disadvantages depending on the particular reaction under investigation. Summaries of some of the main methods are given below.

Read more about this topic:  Transition State

Famous quotes containing the words transition, states and/or chemistry:

    The most remarkable aspect of the transition we are living through is not so much the passage from want to affluence as the passage from labor to leisure.... Leisure contains the future, it is the new horizon.... The prospect then is one of unremitting labor to bequeath to future generations a chance of founding a society of leisure that will overcome the demands and compulsions of productive labor so that time may be devoted to creative activities or simply to pleasure and happiness.
    Henri Lefebvre (b. 1901)

    The line that I am urging as today’s conventional wisdom is not a denial of consciousness. It is often called, with more reason, a repudiation of mind. It is indeed a repudiation of mind as a second substance, over and above body. It can be described less harshly as an identification of mind with some of the faculties, states, and activities of the body. Mental states and events are a special subclass of the states and events of the human or animal body.
    Willard Van Orman Quine (b. 1908)

    ...some sort of false logic has crept into our schools, for the people whom I have seen doing housework or cooking know nothing of botany or chemistry, and the people who know botany and chemistry do not cook or sweep. The conclusion seems to be, if one knows chemistry she must not cook or do housework.
    Ellen Henrietta Swallow Richards (1842–1911)