"not periodically" is a correct and usable phrase in written English.
It means something does not occur at regular or consistent intervals. Example: "We do not receive payments for this service periodically, but rather in one lump sum at the end of the year."
Why then should Hamas not periodically use this successful strategy?
It is hard to find anybody who worked in the ballpark who did not like him and did not periodically chat with him.
For example, the report, called a "benchmarking study," notes that "knowledge and operational skill degrade when not periodically recalled or used".
Q. Rather than put the earth's environment at risk, why not periodically shoot small loads of the waste from atomic power plants into space?
Consider the possibility of a living mulch, a perennial cover-crop plant that is not overly competitive or that is not periodically weakened by mowing.
Under the group's proposal, the agents of the new F.B.I. domestic intelligence service would spend their careers in intelligence and counterterrorism and would not periodically rotate into criminal case work.
If the instrument wasn't periodically "rated" — recalibrated — the vessel risked being wrecked by unexpected shoals.
He was not above periodically humiliating himself.
The digits of pi march to infinity in a predestined yet unfathomable code: they do not repeat periodically, seeming to pop up by blind chance, lacking any perceivable order, rule, reason, or design — "random" integers, ad infinitum.
We see no reason to hold the shares... Concerns over the sustainability of growth and value creation are not new, periodically resurfacing, but based on our analysis we do not expect these concerns to allay any time soon.
Ms. O'Donnell does not just periodically trot out the cast of "The Lion King," the monster-hit Disney musical over which she rhapsodizes on a regular basis; she also invites actors in straight plays for a chat and a plug.
