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. 2020 Jun 23;10:10478. doi: 10.1038/s41598-020-66840-x

Author Correction: Optimization of Molecules via Deep Reinforcement Learning

Zhenpeng Zhou 1,3, Steven Kearnes 2, Li Li 2, Richard N Zare 1, Patrick Riley 2,
PMCID: PMC7308285  PMID: 32572065

Correction to: Scientific Reports 10.1038/s41598-019-47148-x, published online 24 July 2019

This Article contains errors.

Penalized logP is reported in this Article for our methods in a non-normalised form. Previous research (which we compared to in the original Tables 1 and 2), starting with JT-VAE1 normalized the logP to be zero mean and unit standard deviation based on the training set. To correctly compare with previous research, our penalized logP was recalculated into a normalised form. This resulted in changes of numerical values for Penalized logP in Table 1, and numerical values for MolDQN-naïve and MolDQN-bootstrap Improvement in Table 2. The corrected versions of these tables are included below as Tables 1 and 2.

Table 1.

Top three unique molecule property scores found by each method.

Penalized logP QED
1st 2nd 3rd Validity 1st 2nd 3rd Validity
random walka −0.65 −1.72 −1.88 100% 0.64 0.56 0.56 100%
greedyb 9.05 100% 0.39 100%
ε-greedy, ε = 0.1b 9.10 9.05 9.05 100% 0.914 0.910 0.906 100%
JT-VAEc 5.30 4.93 4.49 100% 0.925 0.911 0.910 100%
ORGANc 3.63 3.49 3.44 0.4% 0.896 0.824 0.820 2.2%
GCPNc 7.98 7.85 7.80 100% 0.948 0.947 0.946 100%
MolDQN-naive 8.69 8.68 8.67 100% 0.934 0.931 0.930 100%
MolDQN-bootstrap 9.01 9.01 8.99 100% 0.948 0.944 0.943 100%
MolDQN-bootstrap 0.948 0.948 0.948 100%

a“random walk” is a baseline that chooses a random action for each step.

b“greedy” is a baseline that chooses the action that leads to the molecule with the highest reward for each step. “ε-greedy” follows the “random” policy with probability ε, and “greedy” policy with probability 1–ε. In contrast, the ε-greedy MolDQN models choose actions based on predicted Q-values rather than rewards.

cvalues are reported in You et al.2.

Table 2.

Mean and standard deviation of penalized logP improvement in constrained optimization tasks.

δ JT-VAEa GCPNa MolDQN-naive MolDQN-bootstrap
Improvement Success Improvement Success Improvement Success Improvement Success
0.0 1.91 ± 2.04 97.5% 4.20 ± 1.28 100% 4.83 ± 1.30 100% 4.88 ± 1.30 100%
0.2 1.68 ± 1.85 97.1% 4.12 ± 1.19 100% 3.79 ± 1.32 100% 3.80 ± 1.30 100%
0.4 0.84 ± 1.45 83.6% 2.49 ± 1.30 100% 2.34 ± 1.18 100% 2.44 ± 1.25 100%
0.6 0.21 ± 0.71 46.4% 0.79 ± 0.63 100% 1.40 ± 0.92 100% 1.30 ± 0.98 100%

δ is the threshold of the similarity constraint SIM(m,m0) ≥ δ. The success rate is the percentage of molecules satisfying the similarity constraint.

avalues are reported in You et al.2.

Additionally, in the Discussion, subsection “Constrained optimization”:

“Using Welch’s t-test30 for N = 800 molecules, we found that both variants of MolDQN gives a highly statistically significant improvement over GCPN for all values of δ with t < −8. The bootstrap variant also significantly outperforms the naive model (except for δ = 0.2) with t < −3.”

should read:

“Using Welch’s t-test30, we found that on δ = 0.2, both variants of MolDQN gives a statistically significant lower improvement comparing to GCPN with P < 1e-7; on δ = 0.4, the differences are insignificant at a 1% level with P = 0.016 for MolDQN naive and P = 0.43 for MolDQN bootstrap; on δ = 0.0 and 0.6, both variants of MolDQN gives a statistically significant higher improvement comparing to GCPN with P < 1e-22. The differences between two variants of MolDQN are statistically insignificant at a 1% level with P > 0.036.”

Furthermore, Figure S7 was updated. The corrected version is shown below as Figure 1.

Figure 1.

Figure 1

.

Lastly, References 13 and 18 were incorrectly given as:

13. Jin, W., Barzilay, R. & Jaakkola, T. Junction tree variational autoencoder for molecular graph generation. arXiv preprint arXiv:1802.04364 (2018).

18. You, J., Liu, B., Ying, R., Pande, V. & Leskovec, J. Graph convolutional policy network for goal-directed molecular graph generation. arXiv preprint arXiv:1806.02473 (2018).

The correct references are listed below as references 1 and 2.

These changes do not affect the conclusions of the Article.

References

  • 1.Jin, W., Barzilay, R. & Jaakkola, T. Junction Tree Variational Autoencoder for Molecular Graph Generation. In Proceedings of the 35th International Conference on Machine Learning (eds. Dy, J. & Krause, A.) vol. 80, 2323–2332 (PMLR, 2018).
  • 2.You, J., Liu, B., Ying, Z., Pande, V. & Leskovec, J. Graph Convolutional Policy Network for Goal-Directed Molecular Graph Generation. In Advances in Neural Information Processing Systems 31 (eds. Bengio, S. et al.) 6410–6421 (Curran Associates, Inc., 2018).

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