**Shifted Softplus** is an activation function ${\rm ssp}(x) = \ln( 0.5 e^{x} + 0.5 )$, which [SchNet](https://paperswithcode.com/method/schnet) employs as non-linearity throughout the network in order to obtain a smooth potential energy surface. The shifting ensures that ${\rm ssp}(0) = 0$ and improves the convergence of the network. This activation function shows similarity to ELUs, while having infinite order of continuity.

**ZCA Whitening** is an image preprocessing method that leads to a transformation of data such that the covariance matrix $\Sigma$ is the identity matrix, leading to decorrelated features.

Image Source: [Alex Krizhevsky](http://www.cs.toronto.edu/~kriz/learning-features-2009-TR.pdf)

ZCA Whitening

Shifted Softplus

SchNet: A continuous-filter convolutional neural network for modeling quantum interactions

Diffusion models applied to latent spaces, which are normally built with (Variational) Autoencoders.

Source	SchNet: A continuous-filter convolutional neural network for modeling quantum interactions
Year	2000
Data Source	CC BY-SA - https://paperswithcode.com