What are some stand-alone, non-series sci Fi stories that could also count as horror lit?

A fave sci Fi story of mine is one from years ago called something like Radiant Doors. In it, Earth has become so overpopulated that certain people are forced to live on Grain ships which are vessels that orbit the planet. Inhabitants have no future and are basically warehoused until they die. The vibe is just creepy. And not every genre author can pull off science And horror in the same package. I would love to find more stories like this.