# Chapter 23 Predicting Molecular Properties

The competition was hosted by a group of UK universities as a featured competition at https://www.kaggle.com/c/champs-scalar-coupling and was subtitled “Can you measure the magnetic interactions between a pair of atoms?”

• Hosts:
• CHemistry and Mathematics in Phase Space (CHAMPS) University of Bristol
• Cardiff University
• Imperial College
• University of Leeds

The price money was \$30,000, the competition ended 21.08.2019 and 2,749 teams had submitted a solution.

• Challenge
• Develop algorithm that can predict the magnetic interaction between two atoms in a molecule
• Data
• dipole moments
• magnetic shielding tensor
• mulliken charge
• potential energy
• Benefit
• designing molecules to carry out specific cellular tasks
• designing better drug molecules

The metric was Log of the Mean Absolute Error (MAE), calculated for each scalar coupling type, and then averaged across types, so that a 1% decrease in MAE for one type provides the same improvement in score as a 1% decrease for another type.

$Log MAE = score=\frac{1}{T} \sum_{t=1}^{T} \log \left(\frac{1}{n_{t}} \sum_{i=1}^{n_{t}}\left|y_{i}-\hat{y}_{i}\right|\right)$

Where:
• $$T$$ is the number of scalar coupling types
• $$n_t$$: is the number of observations of type $$t$$
• $$y_i$$: is the actual scalar coupling constant for the observation
• $$\hat{y}_{i}$$ is the predicted scalar coupling constant for the observation

The best possible score for perfect predictions is approximately -20.7232. The leader board look as follows:

1. -3.23968
2. -3.22349
3. -3.19498

The winning solution is described in the next chapter