What's the opposite of 不安? 不安 (bù​ān)​
CC-CEDICT: unpeaceful / unstable / uneasy / disturbed / restless / worried

Sometimes I want to use the opposite adjective to 不安 (with the meaning 不不安), but I'm not sure what to use.  It's likely not 不不安 nor just 安, but there's a lot of other possibilities like 安静, 安宁, 安详, etc., but none seem to be a great fit.
Question: What is the opposite of 不安?
不安 mean uneasy, restless. The close opposite is 鎮定, which means a person with a stable mental state when facing either expected or unexpected events (can be any mind-stimulating event but usually bad things or news).
The complete opposite is 安然, which means at ease.