Archimedes Tech SPAC Partners II Co. filed an amendment to its Form S-4 registration statement with the SEC on September 2, 2026, covering its proposed business combination with Forge Nano. The filing includes a preliminary proxy statement and prospectus and has not been declared effective. ATII Holdings Inc., Archimedes II’s wholly owned subsidiary, and Forge Nano are the filing entities. Forge Nano develops Atomic Layer Deposition (ALD), a method for applying ultra-thin material layers, for AI-era chip manufacturing and defense battery applications through its Atomic Armor platform. Archimedes II completed a $230 million IPO in February 2025 and trades on Nasdaq under ATIIU, ATII and ATIIW. The transaction remains subject to regulatory, shareholder and other closing conditions, and the companies highlighted extensive risks that could prevent completion or affect the combined company’s performance.