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CH4 ['a2', 'b83', 'n16', 'n2']
C2H6 ['a1', 'a2', 'b1', 'b83', 'n16', 'n2', 't3']
C3H8 ['a1', 'a2', 'b1', 'b83', 'n16', 'n2', 't3', 't4']
C4H10 ['a1', 'a2', 'b1', 'b83', 'n16', 'n2', 't2', 't3', 't4']
C5H12 ['a1', 'a2', 'b1', 'b83', 'n16', 'n2', 't2', 't3', 't4']
C6H14 ['a1', 'a2', 'b1', 'b83', 'n16', 'n2', 't2', 't3', 't4']
C7H16 ['a1', 'a2', 'b1', 'b83', 'n16', 'n2', 't2', 't3', 't4']

C3H6 ['a3', 'a4', 'a6', 'b1', 'b83', 'n16', 'n2', 't15', 't16']
C4H8 ['a2', 'a7', 'a9', 'b1', 'b83', 'n16', 'n2', 't2', 't3', 't4']
C5H10 ['a1', 'a2', 'b1', 'b83', 'n16', 'n2', 't2', 't3', 't4']
C6H12 ['a1', 'a2', 'b1', 'b83', 'n16', 'n2', 't2', 't3', 't4']
C7H14 ['a1', 'a2', 'b1', 'b83', 'n16', 'n2', 't2', 't3', 't4']
C8H16 ['a1', 'a2', 'b1', 'b83', 'n16', 'n2', 't2', 't3', 't4']
C9H18 ['a1', 'a2', 'b1', 'b83', 'n16', 'n2', 't2', 't3', 't4']

Another subset with just a1(C-C-C) matching molecules

Removing CH4, C3H6, C4H8 from the set and with rest of the molecules that match to a1

Parameter

Initial values taken

Linear + cyclo alkanes

Cyclo alkanes only

Linear alkanes only

Std. dev. of the three

1.3.0 for reference

a1, angle, [*:1]-[#6X4:2]-[*:3]

100

114.95

113.98

114.70

0.41

113.66

a1, k, [*:1]-[#6X4:2]-[*:3]

90

91.75

96.28

100.85

3.71

99.23

Test fits with sulfonamide (optimizing only a30, a31)

...

  1. refit using all the targets (td + opt + vib freq)

  2. refit with only opt_geo targets

  3. refit with only vib_freq targets

  4. refit with only td targets

  5. refit with td+opt_geo targets

  6. test fit with a child parameter for a30

    1. a30b *=[#16X4]=* initial value for angle parameter as 125 degrees, and k same as a30 (140)

Fits in progress, most of them crossed five iterations and obj. function values are converging, parameter values at the last iteration as of now (will update after the runs complete)

completed

Initial values

td+opt+vib

opt

vib freq

td

td+opt

td+opt+vib + child

opt only with child param

Frostt99

1

2

3

4

5

6

7

a30, angle

109.5

113.

3

0

109

108.9

114

115.

6

9

109.

6

9

113.1

113.0

112

113.

5

1

a30, k

140.0

147

150.

1

0

162

171.

7

1

165

166.

2

9

95.

9

4

139.7

173

172.2

235.9

a31, angle

109.5

107.

7

5

102

101.

0

1

113

114.

9

0

110

111.

8

4

107.5

110.4

109

110.

9

0

a31, k

120.0

122.

8

1

150

153.

9

5

205

204.

0

2

35

37.

3

0

117.7

115.9

117

128.

5

6

a30b, angle

125.0






123.5

125.

1

7

a30b, k

140.0

177.2






189.7

180.1

X2 values

1.537827e+03

6.716631e+02

5.480947e+02

2.640341e+02

9.816973e+02

1.391896e+03

5.441547e+02

*angle in degrees, k in kcal/mol/rad^2

Comparison of opt only targets' fits with change in forcebalance options

L2 penalty on the objective function for regularization.

penalty_additive: Factor for additive penalty function in objective function. Add a penalty to the objective function (e.g. L2 or L1 norm) with this prefactor. Using an additive penalty requires an assessment of the order of magnitude of the objective function, but it is closer to the
statistical concept of ridge or LASSO regression.

penalty_multiplicative: Factor for multiplicative penalty function in objective function.
Multiply the objective function by (1+X) where X is this value. Using an multiplicative penalty
works well for objective functions of any size but it is not equivalent to statistical regularization methods.

use_pvals: Bypass the transformation matrix (mvals) and use the physical parameters directly


Initial values
Frostt99

#2 in above table

(default option of
1.2.0 fit)




penalty_additive 1.0

penalty_additive 0.0 penalty_multiplicative -1.0

penalty_additive 0.0 penalty_multiplicative -1.0 use_pvals true

a30, angle

109.5

108.9

112.5

-3.66E-04

a30, k

140.0

171.1

150.6

-4.62E-03

a31, angle

109.5

101.1

105.6

4.26E-04

a31, k

120.0

153.5

123.6

7.75E-05

X2 values

6.716631e+02

6.675653e+02

1.821577e+04