This model applies Terminal SNR to its training noise schedule, as described here.
This will not work out-of-the-box (as of June 2023) with Automatic1111's Stable Diffusion WebUI.
It works great using a Diffusers pipeline, such as InvokeAI, or a simple Diffusers python script using DDPMScheduler. One such script is available, here.
I hope that Automatic1111's support for terminal SNR pipelines is improved someday, because SDXL will require it.