Conformer Search (GOAT)#
构象搜索（GOAT）

For flexible molecules, it is important to identify the low energy conformational space to provide the most accurate model of the investigated system. The global optimizer algorithm (GOAT) within ORCA can help to automatically find the global minimum structure and the ensemble around it. GOAT can be envoked by the simple input keyword GOAT:
对于柔性分子，识别低能构象空间至关重要，以提供所研究系统的最准确模型。ORCA 中的全局优化算法（GOAT）能够自动寻找全局最小结构及其周围的集合。通过简单的输入关键词 GOAT 即可调用 GOAT。

!GOAT XTB

*XYZFILE 0 1 inp.xyz

Note 注释

As a GOAT run involves a large number of geometry optimizations, it is recommended to parallelize the calculation, e.g. via the PAL4 keyword. Further, specifically for large systems, the usage of fast semi-empirical methods like GFN2-xTB speeds up the calculation. Nevertheless, GOAT can be used with any method in ORCA that is capable of optimizing geometries.
由于 GOAT 运行涉及大量几何优化，建议通过 PAL4 关键字等方法进行并行计算。此外，对于大型系统，使用 GFN2-xTB 等快速半经验方法可加速计算。尽管如此，GOAT 仍可与 ORCA 中任何具备优化几何能力的方法结合使用。

Example: Diclofenac# 示例：双氯芬酸 #

As an example, we will use to find the global minimum conformation of Diclofenac starting from the PubChem structure.
作为一个示例，我们将从 PubChem 结构出发，寻找双氯芬酸的全局最小构象。

../_images/diclofenac.png — Figure: Diclofenac 图：双氯芬酸#

The input looks like:
输入看起来像：

!GOAT XTB

*XYZFILE 0 1 diclofenac.xyz

After the successful GOAT run, the global minimum structure is stored in the basename.globalminimum.xyz file and the full structure ensemble in the basename.finalensemble.xyz file. In this case, GOAT found 17 unique conformers. The corresponding energies and weights are reported in the output file:
在成功完成 GOAT 运行后，全局最小结构存储在 basename.globalminimum.xyz 文件中，而完整结构集合则存储在 basename.finalensemble.xyz 文件中。在此情况下，GOAT 发现了 17 个独特的构象。相应的能量和权重在输出文件中报告：

                     ------------------------------
                                           _
                                          | |
                          __ _  ___   __ _| |_
                         / _` |/ _ \ / _` | __|
                        | (_| | (_) | (_| | |_
                         \__, |\___/ \__,_|\__|
                         __/ |
                        |___/

                      A Global Optimizer Algorithm
                     ------------------------------
[...]
                Global minimum found!
                Writing structure to diclofenac.globalminimum.xyz

                # Final ensemble info #
                Conformer     Energy     Degen.   % total   % cumul.
                              (kcal/mol)
                ------------------------------------------------------
                        0     0.000          1      75.54      75.54
                        1     0.976          1      14.56      90.10
                        2     1.991          1       2.62      92.72
                        3     2.028          1       2.46      95.18
                        4     2.413          1       1.29      96.47
                        5     2.572          1       0.98      97.45
                        6     2.621          1       0.91      98.36
                        7     2.799          1       0.67      99.03
                        8     3.339          1       0.27      99.30
                        9     3.420          1       0.24      99.53
                       10     3.781          1       0.13      99.66
                       11     3.827          1       0.12      99.78
                       12     4.027          1       0.08      99.86
                       13     4.373          1       0.05      99.91
                       14     4.614          1       0.03      99.94
                       15     4.624          1       0.03      99.97
                       16     4.752          1       0.02     100.00
                       17     5.951          1       0.00     100.00

                Conformers below 3 kcal/mol: 8
                Lowest energy conformer    : -55.771201 Eh
                Sconf at 298.15 K          :  1.83 cal/(molK)
                Gconf at 298.15 K          : -0.17 kcal/mol

                Writing final ensemble to diclofenac.finalensemble.xyz

We see, that the conformer space of Diclofenac is dominated by the two conformers 1 and 2, with their weights summing up to 90.1 %. The 10 lowest conformers look like:
我们观察到，双氯芬酸的构象空间主要由构象 1 和 2 主导，它们的权重总和达到 90.1%。前 10 个最低能量构象如下所示：

Conformer Search (GOAT)#构象搜索（GOAT）

Example: Diclofenac# 示例：双氯芬酸 #

Structures# 结构

Conformer Search (GOAT)#
构象搜索（GOAT）