chi_groups_for_atom
===================

氨基酸中所有原子在对应侧链转角编码中的索引，其中侧链扭转角编码见 `chi_angles_atoms`。
例如，('ARG', 'N'):[(0, 0)] 代表氨基酸 "ARG" 中"N"原子的编码索引为"ARG"的侧链转角编码的(0,0)位置。


+------------------+-------------------------------------+
| key              | value                               |
+==================+=====================================+
| ('ARG', 'N')     | [(0, 0)]                            |
+------------------+-------------------------------------+
| ('ARG', 'CA')    | [(0, 1), (1, 0)]                    |
+------------------+-------------------------------------+
| ('ARG', 'CB')    | [(0, 2), (1, 1), (2, 0)]            |
+------------------+-------------------------------------+
| ('ARG', 'CG')    | [(0, 3), (1, 2), (2, 1), (3, 0)]    |
+------------------+-------------------------------------+
| ('ARG', 'CD')    | [(1, 3), (2, 2), (3, 1)]            |
+------------------+-------------------------------------+
| ('ARG', 'NE')    | [(2, 3), (3, 2)]                    |
+------------------+-------------------------------------+
| ('ARG', 'CZ')    | [(3, 3)]                            |
+------------------+-------------------------------------+
| ('ASN', 'N')     | [(0, 0)]                            |
+------------------+-------------------------------------+
| ('ASN', 'CA')    | [(0, 1), (1, 0)]                    |
+------------------+-------------------------------------+
| ('ASN', 'CB')    | [(0, 2), (1, 1)]                    |
+------------------+-------------------------------------+
| ('ASN', 'CG')    | [(0, 3), (1, 2)]                    |
+------------------+-------------------------------------+
| ('ASN', 'OD1')   | [(1, 3)]                            |
+------------------+-------------------------------------+
| ('ASP', 'N')     | [(0, 0)]                            |
+------------------+-------------------------------------+
| ('ASP', 'CA')    | [(0, 1), (1, 0)]                    |
+------------------+-------------------------------------+
| ('ASP', 'CB')    | [(0, 2), (1, 1)]                    |
+------------------+-------------------------------------+
| ('ASP', 'CG')    | [(0, 3), (1, 2)]                    |
+------------------+-------------------------------------+
| ('ASP', 'OD1')   | [(1, 3)]                            |
+------------------+-------------------------------------+
| ('CYS', 'N')     | [(0, 0)]                            |
+------------------+-------------------------------------+
| ('CYS', 'CA')    | [(0, 1)]                            |
+------------------+-------------------------------------+
| ('CYS', 'CB')    | [(0, 2)]                            |
+------------------+-------------------------------------+
| ('CYS', 'SG')    | [(0, 3)]                            |
+------------------+-------------------------------------+
| ('GLN', 'N')     | [(0, 0)]                            |
+------------------+-------------------------------------+
| ('GLN', 'CA')    | [(0, 1), (1, 0)]                    |
+------------------+-------------------------------------+
| ('GLN', 'CB')    | [(0, 2), (1, 1), (2, 0)]            |
+------------------+-------------------------------------+
| ('GLN', 'CG')    | [(0, 3), (1, 2), (2, 1)]            |
+------------------+-------------------------------------+
| ('GLN', 'CD')    | [(1, 3), (2, 2)]                    |
+------------------+-------------------------------------+
| ('GLN', 'OE1')   | [(2, 3)]                            |
+------------------+-------------------------------------+
| ('GLU', 'N')     | [(0, 0)]                            |
+------------------+-------------------------------------+
| ('GLU', 'CA')    | [(0, 1), (1, 0)]                    |
+------------------+-------------------------------------+
| ('GLU', 'CB')    | [(0, 2), (1, 1), (2, 0)]            |
+------------------+-------------------------------------+
| ('GLU', 'CG')    | [(0, 3), (1, 2), (2, 1)]            |
+------------------+-------------------------------------+
| ('GLU', 'CD')    | [(1, 3), (2, 2)]                    |
+------------------+-------------------------------------+
| ('GLU', 'OE1')   | [(2, 3)]                            |
+------------------+-------------------------------------+
| ('HIS', 'N')     | [(0, 0)]                            |
+------------------+-------------------------------------+
| ('HIS', 'CA')    | [(0, 1), (1, 0)]                    |
+------------------+-------------------------------------+
| ('HIS', 'CB')    | [(0, 2), (1, 1)]                    |
+------------------+-------------------------------------+
| ('HIS', 'CG')    | [(0, 3), (1, 2)]                    |
+------------------+-------------------------------------+
| ('HIS', 'ND1')   | [(1, 3)]                            |
+------------------+-------------------------------------+
| ('ILE', 'N')     | [(0, 0)]                            |
+------------------+-------------------------------------+
| ('ILE', 'CA')    | [(0, 1), (1, 0)]                    |
+------------------+-------------------------------------+
| ('ILE', 'CB')    | [(0, 2), (1, 1)]                    |
+------------------+-------------------------------------+
| ('ILE', 'CG1')   | [(0, 3), (1, 2)]                    |
+------------------+-------------------------------------+
| ('ILE', 'CD1')   | [(1, 3)]                            |
+------------------+-------------------------------------+
| ('LEU', 'N')     | [(0, 0)]                            |
+------------------+-------------------------------------+
| ('LEU', 'CA')    | [(0, 1), (1, 0)]                    |
+------------------+-------------------------------------+
| ('LEU', 'CB')    | [(0, 2), (1, 1)]                    |
+------------------+-------------------------------------+
| ('LEU', 'CG')    | [(0, 3), (1, 2)]                    |
+------------------+-------------------------------------+
| ('LEU', 'CD1')   | [(1, 3)]                            |
+------------------+-------------------------------------+
| ('LYS', 'N')     | [(0, 0)]                            |
+------------------+-------------------------------------+
| ('LYS', 'CA')    | [(0, 1), (1, 0)]                    |
+------------------+-------------------------------------+
| ('LYS', 'CB')    | [(0, 2), (1, 1), (2, 0)]            |
+------------------+-------------------------------------+
| ('LYS', 'CG')    | [(0, 3), (1, 2), (2, 1), (3, 0)]    |
+------------------+-------------------------------------+
| ('LYS', 'CD')    | [(1, 3), (2, 2), (3, 1)]            |
+------------------+-------------------------------------+
| ('LYS', 'CE')    | [(2, 3), (3, 2)]                    |
+------------------+-------------------------------------+
| ('LYS', 'NZ')    | [(3, 3)]                            |
+------------------+-------------------------------------+
| ('MET', 'N')     | [(0, 0)]                            |
+------------------+-------------------------------------+
| ('MET', 'CA')    | [(0, 1), (1, 0)]                    |
+------------------+-------------------------------------+
| ('MET', 'CB')    | [(0, 2), (1, 1), (2, 0)]            |
+------------------+-------------------------------------+
| ('MET', 'CG')    | [(0, 3), (1, 2), (2, 1)]            |
+------------------+-------------------------------------+
| ('MET', 'SD')    | [(1, 3), (2, 2)]                    |
+------------------+-------------------------------------+
| ('MET', 'CE')    | [(2, 3)]                            |
+------------------+-------------------------------------+
| ('PHE', 'N')     | [(0, 0)]                            |
+------------------+-------------------------------------+
| ('PHE', 'CA')    | [(0, 1), (1, 0)]                    |
+------------------+-------------------------------------+
| ('PHE', 'CB')    | [(0, 2), (1, 1)]                    |
+------------------+-------------------------------------+
| ('PHE', 'CG')    | [(0, 3), (1, 2)]                    |
+------------------+-------------------------------------+
| ('PHE', 'CD1')   | [(1, 3)]                            |
+------------------+-------------------------------------+
| ('PRO', 'N')     | [(0, 0)]                            |
+------------------+-------------------------------------+
| ('PRO', 'CA')    | [(0, 1), (1, 0)]                    |
+------------------+-------------------------------------+
| ('PRO', 'CB')    | [(0, 2), (1, 1)]                    |
+------------------+-------------------------------------+
| ('PRO', 'CG')    | [(0, 3), (1, 2)]                    |
+------------------+-------------------------------------+
| ('PRO', 'CD')    | [(1, 3)]                            |
+------------------+-------------------------------------+
| ('SER', 'N')     | [(0, 0)]                            |
+------------------+-------------------------------------+
| ('SER', 'CA')    | [(0, 1)]                            |
+------------------+-------------------------------------+
| ('SER', 'CB')    | [(0, 2)]                            |
+------------------+-------------------------------------+
| ('SER', 'OG')    | [(0, 3)]                            |
+------------------+-------------------------------------+
| ('THR', 'N')     | [(0, 0)]                            |
+------------------+-------------------------------------+
| ('THR', 'CA')    | [(0, 1)]                            |
+------------------+-------------------------------------+
| ('THR', 'CB')    | [(0, 2)]                            |
+------------------+-------------------------------------+
| ('THR', 'OG1')   | [(0, 3)]                            |
+------------------+-------------------------------------+
| ('TRP', 'N')     | [(0, 0)]                            |
+------------------+-------------------------------------+
| ('TRP', 'CA')    | [(0, 1), (1, 0)]                    |
+------------------+-------------------------------------+
| ('TRP', 'CB')    | [(0, 2), (1, 1)]                    |
+------------------+-------------------------------------+
| ('TRP', 'CG')    | [(0, 3), (1, 2)]                    |
+------------------+-------------------------------------+
| ('TRP', 'CD1')   | [(1, 3)]                            |
+------------------+-------------------------------------+
| ('TYR', 'N')     | [(0, 0)]                            |
+------------------+-------------------------------------+
| ('TYR', 'CA')    | [(0, 1), (1, 0)]                    |
+------------------+-------------------------------------+
| ('TYR', 'CB')    | [(0, 2), (1, 1)]                    |
+------------------+-------------------------------------+
| ('TYR', 'CG')    | [(0, 3), (1, 2)]                    |
+------------------+-------------------------------------+
| ('TYR', 'CD1')   | [(1, 3)]                            |
+------------------+-------------------------------------+
| ('VAL', 'N')     | [(0, 0)]                            |
+------------------+-------------------------------------+
| ('VAL', 'CA')    | [(0, 1)]                            |
+------------------+-------------------------------------+
| ('VAL', 'CB')    | [(0, 2)]                            |
+------------------+-------------------------------------+
| ('VAL', 'CG1')   | [(0, 3)]                            |
+------------------+-------------------------------------+