The phrase "most calmly" is correct and usable in written English.
You can use this phrase to emphasize that an action was done in a very peaceful or tranquil manner. For example, "She handled the difficult situation most calmly."
A similar confab finessed the Sun Records classic "Mystery Train," which arose from an extended fade-out of "Hearts and Bones," one of his most calmly devastating ballads.
Often working with the same actors (especially Kim, who is also his partner, and who is one of the most calmly ferocious and lucidly expressive actors working now), he creates films that are part of his own cinematic universe.
Rather, that would be André Korben (played by Emmanuel Salinger, who's among the most calmly and compactly expressive of modern actors), a film producer and studio boss in his mid-forties who's looking vigorously ahead to the future of the industry and the art of the movies while getting caught in the pull of his own past.
Be able to work quickly (and most importantly calmly) under pressure.
Meyer, for the most part, spoke calmly, dutifully and with a measure of introspection.
Most visitors were calmly escorted out of the zoo by park personnel.
In a concession speech broadcast on state television on Friday night, Mr. Jammeh, one of Africa's most eccentric leaders, calmly accepted his loss.
I am able to respond calmly, most of the time".
Overall most participants were calmly accepting of the discontinuation and the reasons for it.
We go about our digital lives calmly because most people and most companies believe in that integrity most of the time.
The river runs calmly along most of its length.
