NEW GRINCH AB INITIO INTERPRETATION OF ELECTRON DENSITY DATA

格林奇II，直接地图解译。在20世纪80年代初，汤姆 威廉姆斯是GRIP项目的成员，他建造了格林奇系统 用于电子密度图的从头算解释。威廉姆斯的 该系统基于乔纳森·格里尔博士、卡罗尔·约翰逊博士和 斯坦利·斯旺森通过标记电子密度 局部密度较高的山脊。至少有50份这个系统的副本 传播到结晶学社区。研究生 目前GRIP项目团队的Juraj Horacek正在重新审视这一点 用脊线方法解释从头算电子密度 我们开发了新的、功能更强大的脊线查找数学 由David Eberly设计的医学图像分析部门。我们的 新方法与以前的工作的不同之处在于，我们不仅仅是 连接临界点，但实际上跟踪高密度的山脊 通过一个内插函数。这应该有助于我们避免一些 地图解译中常见的几种错误。我们希望这项工作能够 导致电子密度的新表示和新的 将其解释为分子结构的方法。 霍拉切克决定放弃或推迟他的博士工作，以便 进入康奈尔商学院。他从五月份开始从事这个项目。 一直到九月。他可能会在今年夏天再次致力于这项工作。我们等着瞧吧。 我们现在不指望另一个学生拿起这份作业；如果不是， 此子项目将被放弃。

GRINCH II, Direct Map Interpretation. In the early 1980s Tom Williams, while a member of the GRIP project, built the GRINCH system for the ab-initio interpretation of electron density maps. Williams' system was based on work by Drs. Jonathan Greer, Carroll Johnson, and Stanley Swanson for representing electron density by marking the ridges of high local density. At least 50 copies of this system were disseminated to the crystallographic community. Graduate student Juraj Horacek of the current GRIP project team was re-examining this ridge line approach to ab-initio electron density interpretation using new, more powerful ridge line finding mathematics developed in our department by David Eberly for the analysis of medical images. Our new approach is distinguished from prior work in that we do not simply connect critical points but actually trace the ridges of high density through an interpolated function. This should help us avoid some kinds of common errors in map interpretation. We expect this work to lead to both new representations for electron density and to new methodologies for its interpretation as a molecular structure. Horacek decided to abandon or postpone his Ph.D. work in order to enter Cornell Business School. He worked on the project from May until September. He may work on it again this summer. We shall see. We do not now expect another student to pick up this work; if not, this subproject will be abandoned.