Statement of Changes in Beneficial Ownership (Form 4)

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b). Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person * Zimmermann Curtis J. 2. Issuer Name and Ticker or Trading Symbol Forge Nano Holdings, Inc. [NANO] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) Chief Legal Counsel (Last) (First) (Middle) C/O FORGE NANO HOLDINGS, INC., 12300 GRANT STREET, SUITE 110 3. Date of Earliest Transaction (Month/Day/Year) 10/22/2026 (Street) THORNTON, CO 80241 4. If Amendment, Date Original Filed (Month/Day/Year) 6. Individual or Joint/Group Filing (Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Stock Option (right to buy)

$0.56

10/22/2026

A

308,608

10/22/2026

01/11/2032

Common Stock

308,608

(1)

308,608

D

Stock Option (right to buy)

$0.56

10/22/2026

A

26,358

10/22/2026

04/25/2032

Common Stock

26,358

(1)

26,358

D

Stock Option (right to buy)

$1.03

10/22/2026

A

19,946

(2)

03/31/2034

Common Stock

19,946

(1)

19,946

D

Stock Option (right to buy)

$1.33

10/22/2026

A

170,603

(3)

12/11/2034

Common Stock

170,603

(1)

170,603

D

Stock Option (right to buy)

$2.94

10/22/2026

A

12,823

(4)

10/23/2035

Common Stock

12,823

(1)

12,823

D

Stock Option (right to buy)

$2.94

10/22/2026

A

25,361

(5)

03/29/2036

Common Stock

25,361

(1)

25,361

D

Performance Stock Units

(6)

10/22/2026

A

321,601

(6)

10/22/2031

Common Stock

321,601

(6)

321,601

D

Performance Stock Units

(7)(8)

10/22/2026

A

101,176

(7)(8)

10/22/2031

Common Stock

101,176

(7)(8)

101,176

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Zimmermann Curtis J. C/O FORGE NANO HOLDINGS, INC. 12300 GRANT STREET, SUITE 110 THORNTON, CO 80241			Chief Legal Counsel

Signatures

/s/ Michael Kleinberg, as Attorney-in-fact for Curtis Zimmermann		10/26/2026
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	Consists of stock options granted under the 2017 Equity Incentive Plan of Forge Nano, Inc. ("Forge Nano") that were converted into stock options exercisable for shares of the Issuer's common stock in connection with the Issuer's business combination (the "Business Combination") pursuant to the Agreement and Plan of Merger dated April 20, 2026, by and among Archimedes Tech SPAC Partners II Co., the Issuer (f/k/a ATII Holdings Inc.), ATII Merger Sub Inc., ATII Merger Sub II, LLC and Forge Nano (the "Merger Agreement"), and are exercisable following the closing of the Business Combination.
(2)	25% of these stock options vested on April 1, 2025, and the remaining 75% vested and will vest in 36 substantially equal monthly installments thereafter, subject to the Reporting Person's continued service with the Issuer.
(3)	25% of these stock options vested on December 12, 2025, and the remaining 75% vested and will vest in 36 substantially equal monthly installments thereafter, subject to the Reporting Person's continued service with the Issuer.
(4)	25% of these stock options vested on October 1, 2026, and the remaining 75% will vest in 36 substantially equal monthly installments thereafter, subject to the Reporting Person's continued service with the Issuer.
(5)	25% of these stock options will vest on March 31, 2027, and the remaining 75% will vest in 36 substantially equal monthly installments thereafter, subject to the Reporting Person's continued service with the Issuer.
(6)	Represents performance stock units, each representing a right to receive one share of common stock of the Issuer, granted to holders of Forge Nano stock options in connection with the Business Combination. The performance stock units will vest as follows: (i) one third of the performance stock units will vest if the VWAP of the Common Stock equals or exceeds $15.00 per share over any 30 trading day period or the revenue of the Issuer for the preceding twelve months equals or exceeds $400,000,000, (ii) one third of the performance stock units will vest if the VWAP of the Common Stock equals or exceeds $20.00 per share over any 30 trading day period or the revenue of the Issuer for the preceding twelve months equals or exceeds $600,000,000 and (iii) one third of the performance stock units will vest if the VWAP of the Common Stock equals or exceeds $25.00 per share over any 30 trading day period or the revenue of the Issuer for the preceding twelve months equals or exceeds $800,000,000.
(7)	Represents performance stock units, each representing a right to receive one share of common stock of the Issuer, granted to holders of Forge Nano stock options in connection with the Business Combination. The performance stock units will vest as follows, subject to the Reporting Person's continued service with the Issuer through each applicable vesting event: (i) one third of the performance stock units will vest if the VWAP of the Common Stock equals or exceeds $15.00 per share over any 30 trading day period or the revenue of the Issuer for the preceding twelve months equals or exceeds $400,000,000, (ii) one third of the performance stock units will vest if the VWAP of the Common Stock equals or exceeds $20.00 per share over any 30 trading day period or the revenue of the Issuer (Cont'd in FN9)
(8)	(Cont'd from FN8) for the preceding twelve months equals or exceeds $600,000,000 and (iii) one third of the performance stock units will vest if the VWAP of the Common Stock equals or exceeds $25.00 per share over any 30 trading day period or the revenue of the Issuer for the preceding twelve months equals or exceeds $800,000,000.

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