(not) even for a moment; (not) on any account; (not) the least bit
Used with a negative predicate to strongly deny a possibility. Emphasizes that something is absolutely not the case.
at any rate; at the very least; if ... at all
Used to set a minimal condition or expectation. Often implies 'even if nothing else, at least this should hold'.
I haven't thought about such a thing for even a moment.
You must not doubt him on any account.
At the very least, since you made a promise, you should keep it.
If you are a teacher at all, you wouldn't say such a thing.