Table 3 VALIDITY and CORRELATION (see the section “Evaluation metrics” for definitions) for the RNN (recurrent neural network) and Transformer models, considering similarity k1 and k2 trained with and without ranking loss

From: Exhaustive local chemical space exploration using a transformer model

Model

Similarity

Ranking loss

Validity

Correlation

RNN

k1

× 

0.90

0.10 ± 0.25

RNN

k1

0.71

0.22 ± 0.30

RNN

k2

× 

0.88

0.18 ± 0.24

RNN

k2

0.75

0.33 ± 0.26

Transformer

k1

× 

0.99

0.24 ± 0.17

Transformer

k1

0.99

0.63 ± 0.16

Transformer

k2

× 

0.99

0.09 ± 0.14

Transformer

k2

0.99

0.42 ± 0.22

  1. k1 is the Tanimoto similarity kernel, while k2 is the kernel induced by the autoencoder. By training the models with ranking loss the correlation consistently improves, while the validity remains the same for the Transformer and decreased for the RNN. The best results are highlighted in bold.