[tt] [Perry E. Metzger] [Act] The paper is out.

[Eugen Leitl]

From: "Perry E. Metzger" <perry at piermont.com>
Date: Mon, 21 Apr 2008 12:01:57 -0400
To: Anarcho-Capitalist Transhumanists <act at crackmuppet.org>
Cc: Russell Whitaker <russell.whitaker at gmail.com>
Subject: [Act] The paper is out.
User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.1 (berkeley-unix)


"Perry E. Metzger" <perry at piermont.com> writes:
> Merkle and Freitas are about to publish a paper on nine tooltips that
> can construct each other. I have a preprint. (No, I can't give it out,
> I'm not allowed to.) I'll post on that when it becomes feasible. The
> paper is quite amazing -- it is over 100 pages long, and required over
> 105,000 hours of compute time to do the simulations.

It appears the paper has now been published. See: http://www.aspbs.com/ctn/

Unfortunately the journal it is in is slightly difficult to get one's
hands on.

A Minimal Toolset for Positional Diamond Mechanosynthesis
Freitas, Robert A.; Merkle, Ralph C.
Journal of Computational and Theoretical Nanoscience, Volume
5, Number 5, May 2008 , pp. 760-861(102)
DOI: 10.1166/jctn.2008.002

Abstract:
   This paper presents the first theoretical quantitative systems
   level study of a complete suite of reaction pathways for
   scanning-probe based ultrahigh-vacuum diamond mechanosynthesis
   (DMS). A minimal toolset is proposed for positionally controlled
   DMS consisting of three primary tools-the (1) Hydrogen Abstraction
   (HAbst), (2) Hydrogen Donation (HDon), and (3) Dimer Placement
   (DimerP) tools-and six auxiliary tools-the (4) Adamantane radical
   (AdamRad) and (5) Germyladamantane radical (GeRad) handles, the (6)
   Methylene (Meth), (7) Germylmethylene (GM), and (8) Germylene
   (Germ) tools, and (9) the Hydrogen Transfer (HTrans) tool which is
   a simple compound of two existing tools (HAbst + GeRad). Our
   description of this toolset, the first to exhibit 100% process
   closure, explicitly specifies all reaction steps and reaction
   pathologies, also for the first time. The toolset employs three
   element types (C, Ge, and H) and requires inputs of four feedstock
   molecules-CH4 and C2H2 as carbon sources, Ge2H6 as the germanium
   source, and H2 as a hydrogen source. The present work shows that
   the 9-tooltype toolset can, using only these simple bulk-produced
   chemical inputs: (1) fabricate all nine tooltypes, including their
   adamantane handle structures and reactive tool intermediates,
   starting from a flat passivated diamond surface or an adamantane
   seed structure; (2) recharge all nine tooltypes after use; and (3)
   build both clean and hydrogenated molecularly-precise unstrained
   cubic diamond C(111)/C(110)/C(100) and hexagonal diamond surfaces
   of process-unlimited size, including some Ge-substituted variants;
   methylated and ethylated surface structures; handled polyyne,
   polyacetylene and polyethylene chains of process-unlimited length;
   and both flat graphene sheet and curved graphene
   nanotubes. Reaction pathways and transition geometries involving
   1620 tooltip/workpiece structures were analyzed using Density
   Functional Theory (DFT) in Gaussian 98 at the B3LYP/6-311+G(2d,p)
   // B3LYP/3-21G* level of theory to compile 65 Reaction Sequences
   comprised of 328 reaction steps, 354 unique pathological side
   reactions and 1321 reported DFT energies. The reactions should
   exhibit high reliability at 80 K and moderate reliability at 300
   K. This toolset provides clear developmental targets for a
   comprehensive near-term DMS implementation program.


Perry
_______________________________________________
Act mailing list
Act at lists.crackmuppet.org
http://lists.crackmuppet.org/listinfo.cgi/act-crackmuppet.org



----- End forwarded message -----
-- 
Eugen* Leitl <a href="http://leitl.org">leitl</a> http://leitl.org
______________________________________________________________
ICBM: 48.07100, 11.36820 http://www.ativel.com http://postbiota.org
8B29F6BE: 099D 78BA 2FD3 B014 B08A  7779 75B0 2443 8B29 F6BE